diff --git a/blockly_compressed.js b/blockly_compressed.js
index c62d70dd0..a900fe285 100644
--- a/blockly_compressed.js
+++ b/blockly_compressed.js
@@ -1079,8 +1079,8 @@ this.bubble_.setBubbleSize(a.width,a.height)}else this.bubble_.dispose(),this.bo
 Blockly.Warning.prototype.dispose=function(){this.block_.warning=null;Blockly.Icon.prototype.dispose.call(this)};Blockly.Block=function(a,b,c){this.id=c&&!a.getBlockById(c)?c:Blockly.genUid();a.blockDB_[this.id]=this;this.previousConnection=this.nextConnection=this.outputConnection=null;this.inputList=[];this.inputsInline=void 0;this.disabled=!1;this.tooltip="";this.contextMenu=!0;this.parentBlock_=null;this.childBlocks_=[];this.editable_=this.movable_=this.deletable_=!0;this.collapsed_=this.isShadow_=!1;this.comment=null;this.xy_=new goog.math.Coordinate(0,0);this.workspace=a;this.isInFlyout=a.isFlyout;this.RTL=
 a.RTL;b&&(this.type=b,c=Blockly.Blocks[b],goog.asserts.assertObject(c,'Error: "%s" is an unknown language block.',b),goog.mixin(this,c));a.addTopBlock(this);goog.isFunction(this.init)&&this.init();this.inputsInlineDefault=this.inputsInline;Blockly.Events.isEnabled()&&Blockly.Events.fire(new Blockly.Events.Create(this));goog.isFunction(this.onchange)&&(this.onchangeWrapper_=this.onchange.bind(this),this.workspace.addChangeListener(this.onchangeWrapper_))};
 Blockly.Block.obtain=function(a,b){console.warn("Deprecated call to Blockly.Block.obtain, use workspace.newBlock instead.");return a.newBlock(b)};Blockly.Block.prototype.data=null;Blockly.Block.prototype.colour_="#000000";
-Blockly.Block.prototype.dispose=function(a){this.onchangeWrapper_&&this.workspace.removeChangeListener(this.onchangeWrapper_);this.unplug(a);Blockly.Events.isEnabled()&&Blockly.Events.fire(new Blockly.Events.Delete(this));Blockly.Events.disable();try{this.workspace&&(this.workspace.removeTopBlock(this),delete this.workspace.blockDB_[this.id],this.workspace=null);for(var b=this.childBlocks_.length-1;0<=b;b--)this.childBlocks_[b].dispose(!1);for(var b=0,c;c=this.inputList[b];b++)c.dispose();this.inputList.length=
-0;for(var d=this.getConnections_(!0),b=0;b<d.length;b++){var e=d[b];e.isConnected()&&e.disconnect();d[b].dispose()}}finally{Blockly.Events.enable()}};
+Blockly.Block.prototype.dispose=function(a){if(this.workspace){this.onchangeWrapper_&&this.workspace.removeChangeListener(this.onchangeWrapper_);this.unplug(a);Blockly.Events.isEnabled()&&Blockly.Events.fire(new Blockly.Events.Delete(this));Blockly.Events.disable();try{this.workspace&&(this.workspace.removeTopBlock(this),delete this.workspace.blockDB_[this.id],this.workspace=null);for(var b=this.childBlocks_.length-1;0<=b;b--)this.childBlocks_[b].dispose(!1);for(var b=0,c;c=this.inputList[b];b++)c.dispose();
+this.inputList.length=0;for(var d=this.getConnections_(!0),b=0;b<d.length;b++){var e=d[b];e.isConnected()&&e.disconnect();d[b].dispose()}}finally{Blockly.Events.enable()}}};
 Blockly.Block.prototype.unplug=function(a){if(this.outputConnection)this.outputConnection.isConnected()&&this.outputConnection.disconnect();else if(this.previousConnection){var b=null;this.previousConnection.isConnected()&&(b=this.previousConnection.targetConnection,this.previousConnection.disconnect());var c=this.getNextBlock();a&&c&&(a=this.nextConnection.targetConnection,a.disconnect(),b&&b.checkType_(a)&&b.connect(a))}};
 Blockly.Block.prototype.getConnections_=function(){var a=[];this.outputConnection&&a.push(this.outputConnection);this.previousConnection&&a.push(this.previousConnection);this.nextConnection&&a.push(this.nextConnection);for(var b=0,c;c=this.inputList[b];b++)c.connection&&a.push(c.connection);return a};Blockly.Block.prototype.lastConnectionInStack_=function(){for(var a=this.nextConnection;a;){var b=a.targetBlock();if(!b)return a;a=b.nextConnection}return null};
 Blockly.Block.prototype.bumpNeighbours_=function(){if(this.workspace&&Blockly.dragMode_==Blockly.DRAG_NONE){var a=this.getRootBlock();if(!a.isInFlyout)for(var b=this.getConnections_(!1),c=0,d;d=b[c];c++){d.isConnected()&&d.isSuperior()&&d.targetBlock().bumpNeighbours_();for(var e=d.neighbours_(Blockly.SNAP_RADIUS),f=0,g;g=e[f];f++)d.isConnected()&&g.isConnected()||g.getSourceBlock().getRootBlock()!=a&&(d.isSuperior()?g.bumpAwayFrom_(d):d.bumpAwayFrom_(g))}}};Blockly.Block.prototype.getParent=function(){return this.parentBlock_};
@@ -1163,8 +1163,8 @@ Blockly.DRAG_FREE){b=goog.math.Coordinate.difference(b,this.dragStartXY_);d=this
 (e=k.connection,f=h,g=k.radius)}Blockly.highlightedConnection_&&Blockly.highlightedConnection_!=e&&(Blockly.highlightedConnection_.unhighlight(),Blockly.highlightedConnection_=null,Blockly.localConnection_=null);e&&e!=Blockly.highlightedConnection_&&(e.highlight(),Blockly.highlightedConnection_=e,Blockly.localConnection_=f);this.isDeletable()&&this.workspace.isDeleteArea(a)}a.stopPropagation();a.preventDefault()}};
 Blockly.BlockSvg.prototype.updateMovable=function(){this.isMovable()?Blockly.addClass_(this.svgGroup_,"blocklyDraggable"):Blockly.removeClass_(this.svgGroup_,"blocklyDraggable")};Blockly.BlockSvg.prototype.setMovable=function(a){Blockly.BlockSvg.superClass_.setMovable.call(this,a);this.updateMovable()};Blockly.BlockSvg.prototype.setEditable=function(a){Blockly.BlockSvg.superClass_.setEditable.call(this,a);a=this.getIcons();for(var b=0;b<a.length;b++)a[b].updateEditable()};
 Blockly.BlockSvg.prototype.setShadow=function(a){Blockly.BlockSvg.superClass_.setShadow.call(this,a);this.updateColour()};Blockly.BlockSvg.prototype.getSvgRoot=function(){return this.svgGroup_};
-Blockly.BlockSvg.prototype.dispose=function(a,b){Blockly.Tooltip.hide();Blockly.Field.startCache();var c=this.workspace;Blockly.selected==this&&(this.unselect(),Blockly.terminateDrag_());Blockly.ContextMenu.currentBlock==this&&Blockly.ContextMenu.hide();b&&this.rendered&&(this.unplug(a),this.disposeUiEffect());this.rendered=!1;Blockly.Events.disable();try{for(var d=this.getIcons(),e=0;e<d.length;e++)d[e].dispose()}finally{Blockly.Events.enable()}Blockly.BlockSvg.superClass_.dispose.call(this,a);goog.dom.removeNode(this.svgGroup_);
-Blockly.resizeSvgContents(c);this.svgPathDark_=this.svgPathLight_=this.svgPath_=this.svgGroup_=null;Blockly.Field.stopCache()};
+Blockly.BlockSvg.prototype.dispose=function(a,b){if(this.workspace){Blockly.Tooltip.hide();Blockly.Field.startCache();var c=this.workspace;Blockly.selected==this&&(this.unselect(),Blockly.terminateDrag_());Blockly.ContextMenu.currentBlock==this&&Blockly.ContextMenu.hide();b&&this.rendered&&(this.unplug(a),this.disposeUiEffect());this.rendered=!1;Blockly.Events.disable();try{for(var d=this.getIcons(),e=0;e<d.length;e++)d[e].dispose()}finally{Blockly.Events.enable()}Blockly.BlockSvg.superClass_.dispose.call(this,
+a);goog.dom.removeNode(this.svgGroup_);Blockly.resizeSvgContents(c);this.svgPathDark_=this.svgPathLight_=this.svgPath_=this.svgGroup_=null;Blockly.Field.stopCache()}};
 Blockly.BlockSvg.prototype.disposeUiEffect=function(){this.workspace.playAudio("delete");var a=Blockly.getSvgXY_(this.svgGroup_,this.workspace),b=this.svgGroup_.cloneNode(!0);b.translateX_=a.x;b.translateY_=a.y;b.setAttribute("transform","translate("+b.translateX_+","+b.translateY_+")");this.workspace.getParentSvg().appendChild(b);b.bBox_=b.getBBox();Blockly.BlockSvg.disposeUiStep_(b,this.RTL,new Date,this.workspace.scale)};
 Blockly.BlockSvg.disposeUiStep_=function(a,b,c,d){var e=(new Date-c)/150;1<e?goog.dom.removeNode(a):(a.setAttribute("transform","translate("+(a.translateX_+(b?-1:1)*a.bBox_.width*d/2*e)+","+(a.translateY_+a.bBox_.height*d*e)+") scale("+(1-e)*d+")"),setTimeout(function(){Blockly.BlockSvg.disposeUiStep_(a,b,c,d)},10))};
 Blockly.BlockSvg.prototype.connectionUiEffect=function(){this.workspace.playAudio("click");if(!(1>this.workspace.scale)){var a=Blockly.getSvgXY_(this.svgGroup_,this.workspace);this.outputConnection?(a.x+=(this.RTL?3:-3)*this.workspace.scale,a.y+=13*this.workspace.scale):this.previousConnection&&(a.x+=(this.RTL?-23:23)*this.workspace.scale,a.y+=3*this.workspace.scale);a=Blockly.createSvgElement("circle",{cx:a.x,cy:a.y,r:0,fill:"none",stroke:"#888","stroke-width":10},this.workspace.getParentSvg());
@@ -1248,8 +1248,9 @@ c.onWorkspaceChangeWrapper_=this.resizeEditor_.bind(this);this.workspace_.addCha
 Blockly.FieldTextInput.prototype.onHtmlInputChange_=function(a){a=Blockly.FieldTextInput.htmlInput_;var b=a.value;b!==a.oldValue_?(a.oldValue_=b,this.setValue(b),this.validate_()):goog.userAgent.WEBKIT&&this.sourceBlock_.render();this.resizeEditor_();Blockly.svgResize(this.sourceBlock_.workspace)};
 Blockly.FieldTextInput.prototype.validate_=function(){var a=!0;goog.asserts.assertObject(Blockly.FieldTextInput.htmlInput_);var b=Blockly.FieldTextInput.htmlInput_;this.sourceBlock_&&(a=this.callValidator(b.value));null===a?Blockly.addClass_(b,"blocklyInvalidInput"):Blockly.removeClass_(b,"blocklyInvalidInput")};
 Blockly.FieldTextInput.prototype.resizeEditor_=function(){var a=Blockly.WidgetDiv.DIV,b=this.fieldGroup_.getBBox();a.style.width=b.width*this.workspace_.scale+"px";a.style.height=b.height*this.workspace_.scale+"px";b=this.getAbsoluteXY_();if(this.sourceBlock_.RTL){var c=this.getScaledBBox_();b.x+=c.width;b.x-=a.offsetWidth}b.y+=1;goog.userAgent.GECKO&&Blockly.WidgetDiv.DIV.style.top&&(--b.x,--b.y);goog.userAgent.WEBKIT&&(b.y-=3);a.style.left=b.x+"px";a.style.top=b.y+"px"};
-Blockly.FieldTextInput.prototype.widgetDispose_=function(){var a=this;return function(){var b=Blockly.FieldTextInput.htmlInput_,c=b.value;a.sourceBlock_&&(c=a.callValidator(c),c=null===c?b.defaultValue:c);a.setValue(c);a.sourceBlock_.rendered&&a.sourceBlock_.render();Blockly.unbindEvent_(b.onKeyDownWrapper_);Blockly.unbindEvent_(b.onKeyUpWrapper_);Blockly.unbindEvent_(b.onKeyPressWrapper_);a.workspace_.removeChangeListener(b.onWorkspaceChangeWrapper_);Blockly.FieldTextInput.htmlInput_=null;b=Blockly.WidgetDiv.DIV.style;
-b.width="auto";b.height="auto";b.fontSize=""}};Blockly.FieldTextInput.numberValidator=function(a){console.warn("Blockly.FieldTextInput.numberValidator is deprecated. Use Blockly.FieldNumber instead.");if(null===a)return null;a=String(a);a=a.replace(/O/ig,"0");a=a.replace(/,/g,"");a=parseFloat(a||0);return isNaN(a)?null:String(a)};Blockly.FieldTextInput.nonnegativeIntegerValidator=function(a){(a=Blockly.FieldTextInput.numberValidator(a))&&(a=String(Math.max(0,Math.floor(a))));return a};Blockly.FieldAngle=function(a,b){this.symbol_=Blockly.createSvgElement("tspan",{},null);this.symbol_.appendChild(document.createTextNode("\u00b0"));Blockly.FieldAngle.superClass_.constructor.call(this,a,b)};goog.inherits(Blockly.FieldAngle,Blockly.FieldTextInput);Blockly.FieldAngle.ROUND=15;Blockly.FieldAngle.HALF=50;Blockly.FieldAngle.CLOCKWISE=!1;Blockly.FieldAngle.OFFSET=0;Blockly.FieldAngle.WRAP=360;Blockly.FieldAngle.RADIUS=Blockly.FieldAngle.HALF-1;
+Blockly.FieldTextInput.prototype.widgetDispose_=function(){var a=this;return function(){var b=Blockly.FieldTextInput.htmlInput_,c=b.value;if(a.sourceBlock_)if(c=a.callValidator(c),null===c)c=b.defaultValue;else if(a.onFinishEditing_)a.onFinishEditing_(c);a.setValue(c);a.sourceBlock_.rendered&&a.sourceBlock_.render();Blockly.unbindEvent_(b.onKeyDownWrapper_);Blockly.unbindEvent_(b.onKeyUpWrapper_);Blockly.unbindEvent_(b.onKeyPressWrapper_);a.workspace_.removeChangeListener(b.onWorkspaceChangeWrapper_);
+Blockly.FieldTextInput.htmlInput_=null;b=Blockly.WidgetDiv.DIV.style;b.width="auto";b.height="auto";b.fontSize=""}};Blockly.FieldTextInput.numberValidator=function(a){console.warn("Blockly.FieldTextInput.numberValidator is deprecated. Use Blockly.FieldNumber instead.");if(null===a)return null;a=String(a);a=a.replace(/O/ig,"0");a=a.replace(/,/g,"");a=parseFloat(a||0);return isNaN(a)?null:String(a)};
+Blockly.FieldTextInput.nonnegativeIntegerValidator=function(a){(a=Blockly.FieldTextInput.numberValidator(a))&&(a=String(Math.max(0,Math.floor(a))));return a};Blockly.FieldAngle=function(a,b){this.symbol_=Blockly.createSvgElement("tspan",{},null);this.symbol_.appendChild(document.createTextNode("\u00b0"));Blockly.FieldAngle.superClass_.constructor.call(this,a,b)};goog.inherits(Blockly.FieldAngle,Blockly.FieldTextInput);Blockly.FieldAngle.ROUND=15;Blockly.FieldAngle.HALF=50;Blockly.FieldAngle.CLOCKWISE=!1;Blockly.FieldAngle.OFFSET=0;Blockly.FieldAngle.WRAP=360;Blockly.FieldAngle.RADIUS=Blockly.FieldAngle.HALF-1;
 Blockly.FieldAngle.prototype.dispose_=function(){var a=this;return function(){Blockly.FieldAngle.superClass_.dispose_.call(a)();a.gauge_=null;a.clickWrapper_&&Blockly.unbindEvent_(a.clickWrapper_);a.moveWrapper1_&&Blockly.unbindEvent_(a.moveWrapper1_);a.moveWrapper2_&&Blockly.unbindEvent_(a.moveWrapper2_)}};
 Blockly.FieldAngle.prototype.showEditor_=function(){Blockly.FieldAngle.superClass_.showEditor_.call(this,goog.userAgent.MOBILE||goog.userAgent.ANDROID||goog.userAgent.IPAD);var a=Blockly.WidgetDiv.DIV;if(a.firstChild){var a=Blockly.createSvgElement("svg",{xmlns:"http://www.w3.org/2000/svg","xmlns:html":"http://www.w3.org/1999/xhtml","xmlns:xlink":"http://www.w3.org/1999/xlink",version:"1.1",height:2*Blockly.FieldAngle.HALF+"px",width:2*Blockly.FieldAngle.HALF+"px"},a),b=Blockly.createSvgElement("circle",
 {cx:Blockly.FieldAngle.HALF,cy:Blockly.FieldAngle.HALF,r:Blockly.FieldAngle.RADIUS,"class":"blocklyAngleCircle"},a);this.gauge_=Blockly.createSvgElement("path",{"class":"blocklyAngleGauge"},a);this.line_=Blockly.createSvgElement("line",{x1:Blockly.FieldAngle.HALF,y1:Blockly.FieldAngle.HALF,"class":"blocklyAngleLine"},a);for(var c=0;360>c;c+=15)Blockly.createSvgElement("line",{x1:Blockly.FieldAngle.HALF+Blockly.FieldAngle.RADIUS,y1:Blockly.FieldAngle.HALF,x2:Blockly.FieldAngle.HALF+Blockly.FieldAngle.RADIUS-
@@ -1285,8 +1286,8 @@ goog.dom.createDom("block");c.setAttribute("type","math_change");Blockly.Blocks.
 (c=goog.dom.createDom("block"),c.setAttribute("type","variables_get"),Blockly.Blocks.variables_set&&c.setAttribute("gap",8),d=goog.dom.createDom("field",null,a[e]),d.setAttribute("name","VAR"),c.appendChild(d),b.push(c))}return b};
 Blockly.Variables.generateUniqueName=function(a){a=a.variableList;var b="";if(a.length)for(var c=1,d=0,e="ijkmnopqrstuvwxyzabcdefgh".charAt(d);!b;){for(var f=!1,g=0;g<a.length;g++)if(a[g].toLowerCase()==e){f=!0;break}f?(d++,25==d&&(d=0,c++),e="ijkmnopqrstuvwxyzabcdefgh".charAt(d),1<c&&(e+=c)):b=e}else b="i";return b};
 Blockly.Variables.getUses=function(a,b){for(var c=[],d=b.getAllBlocks(),e=0;e<d.length;e++){var f=d[e].getVars();if(f)for(var g=0;g<f.length;g++){var h=f[g];h&&Blockly.Names.equals(h,a)&&c.push(d[e])}}return c};Blockly.Variables.disposeUses_=function(a){Blockly.Events.setGroup(!0);for(var b=0;b<a.length;b++)a[b].dispose(!0,!1);Blockly.Events.setGroup(!1)};
-Blockly.Variables["delete"]=function(a,b){var c=b.variableList.indexOf(a);if(-1!=c){var d=Blockly.Variables.getUses(a,b);1<d.length&&window.confirm(Blockly.Msg.DELETE_VARIABLE_CONFIRMATION.replace("%1",d.length).replace("%2",a));Blockly.Variables.disposeUses_(d);b.variableList.splice(c,1)}};Blockly.Variables.createVariable=function(a){var b=Blockly.Variables.promptName(Blockly.Msg.NEW_VARIABLE_TITLE,"");return b?(a.createVariable(b),b):null};
-Blockly.Variables.promptName=function(a,b){var c=window.prompt(a,b);c&&(c=c.replace(/[\s\xa0]+/g," ").replace(/^ | $/g,""),c==Blockly.Msg.RENAME_VARIABLE||c==Blockly.Msg.NEW_VARIABLE)&&(c=null);return c};Blockly.FieldVariable=function(a,b){Blockly.FieldVariable.superClass_.constructor.call(this,Blockly.FieldVariable.dropdownCreate,b);this.setValue(a||"")};goog.inherits(Blockly.FieldVariable,Blockly.FieldDropdown);Blockly.FieldVariable.prototype.init=function(){this.fieldGroup_||(Blockly.FieldVariable.superClass_.init.call(this),this.getValue()||this.setValue(Blockly.Variables.generateUniqueName(this.sourceBlock_.isInFlyout?this.sourceBlock_.workspace.targetWorkspace:this.sourceBlock_.workspace)))};
+Blockly.Variables["delete"]=function(a,b){var c=b.variableList.indexOf(a);if(-1!=c){var d=Blockly.Variables.getUses(a,b);if(1<d.length){for(var e=0,f;f=d[e];e++)if("procedures_defnoreturn"==f.type||"procedures_defreturn"==f.type){c=f.getFieldValue("NAME");window.alert(Blockly.Msg.CANNOT_DELETE_VARIABLE_PROCEDURE.replace("%1",a).replace("%2",c));return}window.confirm(Blockly.Msg.DELETE_VARIABLE_CONFIRMATION.replace("%1",d.length).replace("%2",a))}Blockly.Variables.disposeUses_(d);b.variableList.splice(c,
+1)}};Blockly.Variables.createVariable=function(a){var b=Blockly.Variables.promptName(Blockly.Msg.NEW_VARIABLE_TITLE,"");return b?(a.createVariable(b),b):null};Blockly.Variables.promptName=function(a,b){var c=window.prompt(a,b);c&&(c=c.replace(/[\s\xa0]+/g," ").replace(/^ | $/g,""),c==Blockly.Msg.RENAME_VARIABLE||c==Blockly.Msg.NEW_VARIABLE)&&(c=null);return c};Blockly.FieldVariable=function(a,b){Blockly.FieldVariable.superClass_.constructor.call(this,Blockly.FieldVariable.dropdownCreate,b);this.setValue(a||"")};goog.inherits(Blockly.FieldVariable,Blockly.FieldDropdown);Blockly.FieldVariable.prototype.init=function(){this.fieldGroup_||(Blockly.FieldVariable.superClass_.init.call(this),this.getValue()||this.setValue(Blockly.Variables.generateUniqueName(this.sourceBlock_.isInFlyout?this.sourceBlock_.workspace.targetWorkspace:this.sourceBlock_.workspace)))};
 Blockly.FieldVariable.prototype.getValue=function(){return this.getText()};Blockly.FieldVariable.prototype.setValue=function(a){this.sourceBlock_&&Blockly.Events.isEnabled()&&Blockly.Events.fire(new Blockly.Events.Change(this.sourceBlock_,"field",this.name,this.value_,a));this.value_=a;this.setText(a)};
 Blockly.FieldVariable.dropdownCreate=function(){var a=this.sourceBlock_&&this.sourceBlock_.workspace?this.sourceBlock_.workspace.variableList.slice(0):[],b=this.getText();b&&-1==a.indexOf(b)&&a.push(b);a.sort(goog.string.caseInsensitiveCompare);a.push(Blockly.Msg.RENAME_VARIABLE);a.push(Blockly.Msg.DELETE_VARIABLE.replace("%1",b));for(var b=[],c=0;c<a.length;c++)b[c]=[a[c],a[c]];return b};
 Blockly.FieldVariable.prototype.classValidator=function(a){var b=this.sourceBlock_.workspace;if(a==Blockly.Msg.RENAME_VARIABLE){var c=this.getText();Blockly.hideChaff();(a=Blockly.Variables.promptName(Blockly.Msg.RENAME_VARIABLE_TITLE.replace("%1",c),c))&&Blockly.Variables.renameVariable(c,a,b);return null}if(a==Blockly.Msg.DELETE_VARIABLE.replace("%1",this.getText()))return Blockly.Variables["delete"](this.getText(),this.sourceBlock_.workspace),null};Blockly.Generator=function(a){this.name_=a;this.FUNCTION_NAME_PLACEHOLDER_REGEXP_=new RegExp(this.FUNCTION_NAME_PLACEHOLDER_,"g")};Blockly.Generator.NAME_TYPE="generated_function";Blockly.Generator.prototype.INFINITE_LOOP_TRAP=null;Blockly.Generator.prototype.STATEMENT_PREFIX=null;Blockly.Generator.prototype.INDENT="  ";Blockly.Generator.prototype.COMMENT_WRAP=60;Blockly.Generator.prototype.ORDER_OVERRIDES=[];
diff --git a/blocks_compressed.js b/blocks_compressed.js
index 225d8c128..f507ba235 100644
--- a/blocks_compressed.js
+++ b/blocks_compressed.js
@@ -76,7 +76,8 @@ Blockly.Blocks.procedures_defreturn={init:function(){var a=new Blockly.FieldText
 this.setCommentText(Blockly.Msg.PROCEDURES_DEFRETURN_COMMENT);this.setColour(Blockly.Blocks.procedures.HUE);this.setTooltip(Blockly.Msg.PROCEDURES_DEFRETURN_TOOLTIP);this.setHelpUrl(Blockly.Msg.PROCEDURES_DEFRETURN_HELPURL);this.arguments_=[];this.setStatements_(!0);this.statementConnection_=null},setStatements_:Blockly.Blocks.procedures_defnoreturn.setStatements_,updateParams_:Blockly.Blocks.procedures_defnoreturn.updateParams_,mutationToDom:Blockly.Blocks.procedures_defnoreturn.mutationToDom,domToMutation:Blockly.Blocks.procedures_defnoreturn.domToMutation,
 decompose:Blockly.Blocks.procedures_defnoreturn.decompose,compose:Blockly.Blocks.procedures_defnoreturn.compose,getProcedureDef:function(){return[this.getFieldValue("NAME"),this.arguments_,!0]},getVars:Blockly.Blocks.procedures_defnoreturn.getVars,renameVar:Blockly.Blocks.procedures_defnoreturn.renameVar,customContextMenu:Blockly.Blocks.procedures_defnoreturn.customContextMenu,callType_:"procedures_callreturn"};
 Blockly.Blocks.procedures_mutatorcontainer={init:function(){this.appendDummyInput().appendField(Blockly.Msg.PROCEDURES_MUTATORCONTAINER_TITLE);this.appendStatementInput("STACK");this.appendDummyInput("STATEMENT_INPUT").appendField(Blockly.Msg.PROCEDURES_ALLOW_STATEMENTS).appendField(new Blockly.FieldCheckbox("TRUE"),"STATEMENTS");this.setColour(Blockly.Blocks.procedures.HUE);this.setTooltip(Blockly.Msg.PROCEDURES_MUTATORCONTAINER_TOOLTIP);this.contextMenu=!1}};
-Blockly.Blocks.procedures_mutatorarg={init:function(){this.appendDummyInput().appendField(Blockly.Msg.PROCEDURES_MUTATORARG_TITLE).appendField(new Blockly.FieldTextInput("x",this.validator_),"NAME");this.setPreviousStatement(!0);this.setNextStatement(!0);this.setColour(Blockly.Blocks.procedures.HUE);this.setTooltip(Blockly.Msg.PROCEDURES_MUTATORARG_TOOLTIP);this.contextMenu=!1},validator_:function(a){return(a=a.replace(/[\s\xa0]+/g," ").replace(/^ | $/g,""))||null}};
+Blockly.Blocks.procedures_mutatorarg={init:function(){var a=new Blockly.FieldTextInput("x",this.validator_);this.appendDummyInput().appendField(Blockly.Msg.PROCEDURES_MUTATORARG_TITLE).appendField(a,"NAME");this.setPreviousStatement(!0);this.setNextStatement(!0);this.setColour(Blockly.Blocks.procedures.HUE);this.setTooltip(Blockly.Msg.PROCEDURES_MUTATORARG_TOOLTIP);this.contextMenu=!1;a.onFinishEditing_=this.createNewVar_;a.onFinishEditing_("x")},validator_:function(a){return(a=a.replace(/[\s\xa0]+/g,
+" ").replace(/^ | $/g,""))||null},createNewVar_:function(a){var b=this.sourceBlock_;b&&b.workspace&&b.workspace.options&&b.workspace.options.parentWorkspace&&b.workspace.options.parentWorkspace.createVariable(a)}};
 Blockly.Blocks.procedures_callnoreturn={init:function(){this.appendDummyInput("TOPROW").appendField(this.id,"NAME");this.setPreviousStatement(!0);this.setNextStatement(!0);this.setColour(Blockly.Blocks.procedures.HUE);this.setHelpUrl(Blockly.Msg.PROCEDURES_CALLNORETURN_HELPURL);this.arguments_=[];this.quarkConnections_={};this.quarkIds_=null},getProcedureCall:function(){return this.getFieldValue("NAME")},renameProcedure:function(a,b){Blockly.Names.equals(a,this.getProcedureCall())&&(this.setFieldValue(b,
 "NAME"),this.setTooltip((this.outputConnection?Blockly.Msg.PROCEDURES_CALLRETURN_TOOLTIP:Blockly.Msg.PROCEDURES_CALLNORETURN_TOOLTIP).replace("%1",b)))},setProcedureParameters_:function(a,b){var c=Blockly.Procedures.getDefinition(this.getProcedureCall(),this.workspace),e=c&&c.mutator&&c.mutator.isVisible();e||(this.quarkConnections_={},this.quarkIds_=null);if(b)if(goog.array.equals(this.arguments_,a))this.quarkIds_=b;else{if(b.length!=a.length)throw"Error: paramNames and paramIds must be the same length.";
 this.setCollapsed(!1);this.quarkIds_||(this.quarkConnections_={},a.join("\n")==this.arguments_.join("\n")?this.quarkIds_=b:this.quarkIds_=[]);c=this.rendered;this.rendered=!1;for(var d=0;d<this.arguments_.length;d++){var f=this.getInput("ARG"+d);f&&(f=f.connection.targetConnection,this.quarkConnections_[this.quarkIds_[d]]=f,e&&f&&-1==b.indexOf(this.quarkIds_[d])&&(f.disconnect(),f.getSourceBlock().bumpNeighbours_()))}this.arguments_=[].concat(a);this.updateShape_();if(this.quarkIds_=b)for(d=0;d<this.arguments_.length;d++)e=
diff --git a/core/variables.js b/core/variables.js
index 29f5afe47..6f35b383a 100644
--- a/core/variables.js
+++ b/core/variables.js
@@ -289,9 +289,19 @@ Blockly.Variables.delete = function(name, workspace) {
   if (variableIndex != -1) {
     var uses = Blockly.Variables.getUses(name, workspace);
     if (uses.length > 1) {
+      for (var i = 0, block; block = uses[i]; i++) {
+        if (block.type == 'procedures_defnoreturn' ||
+          block.type == 'procedures_defreturn') {
+          var procedureName = block.getFieldValue('NAME');
+          window.alert(
+              Blockly.Msg.CANNOT_DELETE_VARIABLE_PROCEDURE.replace('%1', name).
+              replace('%2', procedureName));
+          return;
+        }
+      }
       window.confirm(
-        Blockly.Msg.DELETE_VARIABLE_CONFIRMATION.replace('%1', uses.length).
-            replace('%2', name));
+          Blockly.Msg.DELETE_VARIABLE_CONFIRMATION.replace('%1', uses.length).
+          replace('%2', name));
     }
     Blockly.Variables.disposeUses_(uses);
     workspace.variableList.splice(variableIndex, 1);
diff --git a/msg/json/en.json b/msg/json/en.json
index 7e5f4ef74..4cb322a5e 100644
--- a/msg/json/en.json
+++ b/msg/json/en.json
@@ -1,7 +1,7 @@
 {
 	"@metadata": {
 		"author": "Ellen Spertus <ellen.spertus@gmail.com>",
-		"lastupdated": "2016-08-09 17:07:03.957507",
+		"lastupdated": "2016-08-11 17:04:14.955398",
 		"locale": "en",
 		"messagedocumentation" : "qqq"
 	},
diff --git a/msg/messages.js b/msg/messages.js
index 36535c70e..fec52185d 100644
--- a/msg/messages.js
+++ b/msg/messages.js
@@ -108,6 +108,8 @@ Blockly.Msg.RENAME_VARIABLE = 'Rename variable...';
 Blockly.Msg.RENAME_VARIABLE_TITLE = 'Rename all "%1" variables to:';
 /// confirm -  Ask the user to confirm their deletion of multiple uses of a variable.
 Blockly.Msg.DELETE_VARIABLE_CONFIRMATION = 'Delete %1 uses of the %2 variable?';
+/// alert - Tell the user that they can't delete a variable because it's part of the definition of a procedure.
+Blockly.Msg.CANNOT_DELETE_VARIABLE_PROCEDURE = 'Can\'t delete the variable \'%1\' because it is part of the definition of the procedure \'%2\'';
 
 // Colour Blocks.
 /// url - Information about colour.