"event" is not defined error in Firefox

see http://stackoverflow.com/questions/20522887/referenceerror-event-is-not-defined-error-in-firefox
"WebKit follows IE's old behavior of using a global symbol for "event", but Firefox doesn't..."

IPython/html/static/widgets/js/widget_string.js

@@ -1,240 +1,240
 // Copyright (c) IPython Development Team.
 // Distributed under the terms of the Modified BSD License.
 
 define([
     "widgets/js/widget",
     "jquery",
     "bootstrap",
 ], function(widget, $){
 
     var HTMLView = widget.DOMWidgetView.extend({  
         render : function(){
             // Called when view is rendered.
             this.update(); // Set defaults.
         },
         
         update : function(){
             // Update the contents of this view
             //
             // Called when the model is changed.  The model may have been 
             // changed by another view or by a state update from the back-end.
             this.$el.html(this.model.get('value')); // CAUTION! .html(...) CALL MANDITORY!!!
             return HTMLView.__super__.update.apply(this);
         },
     });
 
 
     var LatexView = widget.DOMWidgetView.extend({  
         render : function(){
             // Called when view is rendered.
             this.update(); // Set defaults.
         },
         
         update : function(){
             // Update the contents of this view
             //
             // Called when the model is changed.  The model may have been 
             // changed by another view or by a state update from the back-end.
             this.$el.text(this.model.get('value'));
             MathJax.Hub.Queue(["Typeset",MathJax.Hub,this.$el.get(0)]);
 
             return LatexView.__super__.update.apply(this);
         }, 
     });
 
 
     var TextareaView = widget.DOMWidgetView.extend({  
         render: function(){
             // Called when view is rendered.
             this.$el
                 .addClass('widget-hbox');
             this.$label = $('<div />')
                 .appendTo(this.$el)
                 .addClass('widget-hlabel')
                 .hide();
             this.$textbox = $('<textarea />')
                 .attr('rows', 5)
                 .addClass('widget-text form-control')
                 .appendTo(this.$el);
             this.update(); // Set defaults.
 
             this.model.on('msg:custom', $.proxy(this._handle_textarea_msg, this));
             this.model.on('change:placeholder', function(model, value, options) {
                 this.update_placeholder(value);
             }, this);
 
             this.update_placeholder();
         },
 
         _handle_textarea_msg: function (content){
             // Handle when a custom msg is recieved from the back-end.
             if (content.method == "scroll_to_bottom") {
                 this.scroll_to_bottom();                
             }
         },
 
         update_placeholder: function(value) {
             if (!value) {
                 value = this.model.get('placeholder');
             }
             this.$textbox.attr('placeholder', value);
         },
 
         scroll_to_bottom: function (){
             // Scroll the text-area view to the bottom.
             this.$textbox.scrollTop(this.$textbox[0].scrollHeight);
         },
 
         update: function(options){
             // Update the contents of this view
             //
             // Called when the model is changed.  The model may have been 
             // changed by another view or by a state update from the back-end.
             if (options === undefined || options.updated_view != this) {
                 this.$textbox.val(this.model.get('value'));
 
                 var disabled = this.model.get('disabled');
                 this.$textbox.prop('disabled', disabled);
 
                 var description = this.model.get('description');
                 if (description.length === 0) {
                     this.$label.hide();
                 } else {
                     this.$label.text(description);
                     MathJax.Hub.Queue(["Typeset",MathJax.Hub,this.$label.get(0)]);
                     this.$label.show();
                 }
             }
             return TextareaView.__super__.update.apply(this);
         },
         
         events: {
             // Dictionary of events and their handlers.
             "keyup textarea" : "handleChanging",
             "paste textarea" : "handleChanging",
             "cut textarea"   : "handleChanging"
         },
         
         handleChanging: function(e) { 
             // Handles and validates user input.
             
             // Calling model.set will trigger all of the other views of the 
             // model to update.
             this.model.set('value', e.target.value, {updated_view: this});
             this.touch();
         },
     });
 
 
     var TextView = widget.DOMWidgetView.extend({  
         render: function(){
             // Called when view is rendered.
             this.$el
                 .addClass('widget-hbox-single');
             this.$label = $('<div />')
                 .addClass('widget-hlabel')
                 .appendTo(this.$el)
                 .hide();
             this.$textbox = $('<input type="text" />')
                 .addClass('input')
                 .addClass('widget-text form-control')
                 .appendTo(this.$el);
             this.update(); // Set defaults.
             this.model.on('change:placeholder', function(model, value, options) {
                 this.update_placeholder(value);
             }, this);
 
             this.update_placeholder();
         },
 
         update_placeholder: function(value) {
             if (!value) {
                 value = this.model.get('placeholder');
             }
             this.$textbox.attr('placeholder', value);
         },
         
         update: function(options){
             // Update the contents of this view
             //
             // Called when the model is changed.  The model may have been 
             // changed by another view or by a state update from the back-end.
             if (options === undefined || options.updated_view != this) {
                 if (this.$textbox.val() != this.model.get('value')) {
                     this.$textbox.val(this.model.get('value'));
                 }
 
                 var disabled = this.model.get('disabled');
                 this.$textbox.prop('disabled', disabled);
 
                 var description = this.model.get('description');
                 if (description.length === 0) {
                     this.$label.hide();
                 } else {
                     this.$label.text(description);
                     MathJax.Hub.Queue(["Typeset",MathJax.Hub,this.$label.get(0)]);
                     this.$label.show();
                 }
             }
             return TextView.__super__.update.apply(this);
         },
         
         events: {
             // Dictionary of events and their handlers.
             "keyup input"    : "handleChanging",
             "paste input"    : "handleChanging",
             "cut input"      : "handleChanging",
             "keypress input" : "handleKeypress",
             "blur input" : "handleBlur",
             "focusout input" : "handleFocusOut"
         },
         
         handleChanging: function(e) { 
             // Handles user input.
 
             // Calling model.set will trigger all of the other views of the 
             // model to update.
             this.model.set('value', e.target.value, {updated_view: this});
             this.touch();
         },
         
         handleKeypress: function(e) { 
             // Handles text submition
             if (e.keyCode == 13) { // Return key
                 this.send({event: 'submit'});
-                event.stopPropagation();
-                event.preventDefault();
+                e.stopPropagation();
+                e.preventDefault();
                 return false;
             }
         },
 
         handleBlur: function(e) { 
             // Prevent a blur from firing if the blur was not user intended.
             // This is a workaround for the return-key focus loss bug.
             // TODO: Is the original bug actually a fault of the keyboard
             // manager?
             if (e.relatedTarget === null) {
-                event.stopPropagation();
-                event.preventDefault();
+                e.stopPropagation();
+                e.preventDefault();
                 return false;
             }
         },
 
         handleFocusOut: function(e) { 
             // Prevent a blur from firing if the blur was not user intended.
             // This is a workaround for the return-key focus loss bug.
             if (e.relatedTarget === null) {
-                event.stopPropagation();
-                event.preventDefault();
+                e.stopPropagation();
+                e.preventDefault();
                 return false;
             }
         },
     });
 
     return {
         'HTMLView': HTMLView,
         'LatexView': LatexView,
         'TextareaView': TextareaView,
         'TextView': TextView,
     };
 });