addEventListenerPolyfill.js

// Polyfill event.preventDefault & event.addEventListener
  if (!window.addEventListener) {
    (function() {
      if (!Event.prototype.preventDefault) {
        Event.prototype.preventDefault=function() {
          this.returnValue=false;
        };
      }
      if (!Event.prototype.stopPropagation) {
        Event.prototype.stopPropagation=function() {
          this.cancelBubble=true;
        };
      }
      if (!Element.prototype.addEventListener) {
        var eventListeners=[];
        var addEventListener=function(type,listener /*, useCapture (will be ignored) */) {
          var self=this;
          var wrapper=function(e) {
            e.target=e.srcElement;
            e.currentTarget=self;
            if (listener.handleEvent) {
              listener.handleEvent(e);
            } else {
              listener.call(self,e);
            }
          };
          if (type=="DOMContentLoaded") {
            var wrapper2=function(e) {
              if (document.readyState=="complete") {
                wrapper(e);
              }
            };
            document.attachEvent("onreadystatechange",wrapper2);
            eventListeners.push({object:this,type:type,listener:listener,wrapper:wrapper2});
            if (document.readyState=="complete") {
              var e=new Event();
              e.srcElement=window;
              wrapper2(e);
            }
          } else {
            this.attachEvent("on"+type,wrapper);
            eventListeners.push({object:this,type:type,listener:listener,wrapper:wrapper});
          }
        };
        var removeEventListener=function(type,listener /*, useCapture (will be ignored) */) {
          var counter=0;
          while (counter<eventListeners.length) {
            var eventListener=eventListeners[counter];
            if (eventListener.object==this && eventListener.type==type && eventListener.listener==listener) {
              if (type=="DOMContentLoaded") {
                this.detachEvent("onreadystatechange",eventListener.wrapper);
              } else {
                this.detachEvent("on"+type,eventListener.wrapper);
              }
              eventListeners.splice(counter, 1);
              break;
            }
            ++counter;
          }
        };
        Element.prototype.addEventListener=addEventListener;
        Element.prototype.removeEventListener=removeEventListener;
        if (HTMLDocument) {
          HTMLDocument.prototype.addEventListener=addEventListener;
          HTMLDocument.prototype.removeEventListener=removeEventListener;
        }
        if (Window) {
          Window.prototype.addEventListener=addEventListener;
          Window.prototype.removeEventListener=removeEventListener;
        }
      }
    })();
  }