javascript在IE/FF/Chrome的一些兼容问题

1.获取滚动条高度

 var top=document.body.scrollTop||document.documentElement.scrollTop;

2.事件监听

 var addEvent = function (obj, ev ,fn)
 {
     if(obj.attachEvent){
         obj.attachEvent('on'+ev, fn);
     }else{
         obj.addEventListener(ev, fn, false);
     }
 };

3.事件移除

 var removeEvent = function(element, type, handler){
         if (element.removeEventListener) {
             element.removeEventListener(type, handler, false);
         }
         else if (element.detachEvent) {
                 element.detachEvent("on" + type, handler);
         }
         else {
                 element["on" + type] = null;
         }
 }

4.阻止默认事件

 function(event){
         if (event.preventDefault) {
             event.preventDefault();
         }
         else {
             event.returnValue = false;
         }
 }

5.阻止事件冒泡

 function(event){
         if (event.stopPropagation) {
             event.stopPropagation();
         }
         else {
             event.cancelBubble = true;
         }
 }

6.元素的子节点

 var getChildNode=function(obj)
 {
     var childArr = [];
     var l=obj.childNodes.length;
     for (var i=0;i<l;i++)
         {
             if(obj.childNodes[i].nodeType==1)
                 {
                     childArr.push(obj.childNodes[i]);
                 }
         }
     return childArr;
 }