本人初学javascript，还不是很懂，希望大神帮助

function addEvent(obj,type,fn) {
if (typeof obj.addEventListener != "undefined") {

obj.addEventListener(type, fn, false);
}
}

function removeEvent(obj,type,fn) {
if(typeof obj.removeEventListener!="undefined"){

obj.removeEventListener(type,fn,false);
}

这是我写的addEvent和removeEvent事件
Base.prototype.drag=function{
for (var i = 0; i < this.elements.length; i++) {
addEvent(this.elements[i],"mousedown",function (e){
var _this=this;
var diffX=0;
var diffY=0;
diffX = e.clientX - _this.offsetLeft;
diffY = e.clientX - _this.offsetTop;
function move(e) {
var left = e.clientX - diffX;
var top = e.clientY - diffY;
if (left < 0) {
left = 0;
} else if (left > getInner().width - _this.offsetWidth) {
left = getInner().width - _this.offsetWidth;

            }
            if (top < 0) {
                top = 0;
            } else if (top > getInner().height - _this.offsetHeight) {
                top = getInner().height - _this.offsetHeight;

            }
            _this.style.left = left + "px";
            _this.style.top = top + "px";

        }
        function up() {
            removeEvent(document,"mosuemove",move);
            removeEvent(document,"mouseup",up);
        }
                     addEvent(document,"mousemove",move)
         addEvent(document,"mouseup",up);     
                    }）
                    }
                    return this;
                    }


                    点击选中的对象时还未拖动会自动弹到浏览器最上面,会出现所选的 div对象 粘着鼠标的情况，不知道removeEvent为什么没起作用.

var fn = function(){};
addEventListener(type, fn, false)
removeEventListener(type,fn,false);
参数fn必须指向同一个引用