工具函数

var util = {
            addHandler:function(ele,type,handler){
                if(ele.attachEvent){
                    //IE
                    ele.attachEvent('on'+type,handler)                    
                }else{
                    ele.addEventListener(type,handler,false)
                }
            },
            removeHandler:function(ele,type,cb){
                if(ele.detachEvent){
                    ele.detachEvent('on'+type,cb)
                }else{
                    ele.removeEventListener(type,cb,false);
                }
                ele['on'+type] = null;//防止内存泄漏
            },
            getEvent:function (event){
                return event?event:window.event;
            },
            getTarget:function(event){
                return event.target || event.srcElement;
            },
            preventDefault:function (event){
                if(event.preventDefault){
                    event.preventDefault();
                }else{
                    event.returnVauel=false;
                }
            },
            stopPropagation:function (event){
                if (event.stopPropagation){
                    event.stopPropagation(); 
                }else{
                    event.cancleBubble=true;
                }
            }
        }