替换Select标签的javascript类

// 下拉列表类
// PubEdition: Version 1.0.0.0
// ModifyDate: 2009-12-09 9:30:00
// FinishDate: 2009-12-09 9:30:00
// AuthorName: binbin( Mail:pl45@163.com / Tel:13893302154 )
var droplistswap=function(){};
droplistswap.prototype.originalElement=new Array();
// droplistswap.prototype.hidedroplist=function(evt){
// var my = this;
// var _event = window.event?window.event:evt;
// var obj = _event.toElement?_event.toElement:_event.relatedTarget;
// while( obj!=null && obj.id!="droplistElement"){
// obj = obj.parentNode;
// }
// if(obj==null)document.getElementById("droplistElement").style.display="none";
// }
droplistswap.prototype.initialize=function(DropID,index){

var my = this;
my.originalElement.push(document.getElementById(DropID));
var selectElement=document.createElement('div');
selectElement.innerHTML="<label>"+document.getElementById(DropID).options[document.getElementById(DropID).selectedIndex].text+"</label>";
//selectElement.style.position="relative";
selectElement.id="selectElement"+index;
selectElement.className="droplistswap";
//selectElement.style.width="80px";
selectElement.style.top=document.getElementById(DropID).style.top;
selectElement.style.left= document.getElementById(DropID).style.left;

document.getElementById(DropID).parentNode.appendChild(selectElement);

document.getElementById(DropID).style.display="none";
//function的参数名称不能和类成员的参数名称相同
// my.addEventListener(document,"click",function(event){my.hidedroplist.call(my,event)});
my.addEventListener(selectElement,"click",function(event,p_ID,p_Index){my.handledroplist.call(my,event,DropID,index)});
}
droplistswap.prototype.handledroplist=function(evt,DropID,OriIndex)
{
var my = this;
//alert(OriIndex);
var _event = window.event?window.event:evt;
// if( _event == null ||typeof(_event) == 'undefined'){
// var _fun = my