代码中创设一个DIV层

代码中创建一个DIV层
大家好

刚看到一个JS代码.他现在只是能弹出一个图层对话框出来.现在想把他改成同时弹出两个图层.对话框为前景. 另外一个图层为背景.这样出来的效果就会很好看些.
不废话了.上代码



JS代码
=========================================================

<script>
  
  window.addEvent('domready',function(){
  var curLH = location.href;
   
  if(["-?loginBuy\.html"].some(function(r){
  return curLH.test(new RegExp(r));
  })){return false;}
  var MiniPassport = new Object();
var miniPassportDialog = new Element('div',{'class':'dialog mini-passport-dialog','id':'dialog1'}).set('html',$E('#template-modal .dialog').get('html').substitute({
title:'登录',
content:''
})).setStyles({
display:'none',
width:0,
height:'auto'
}).adopt(new Element('iframe',{src:'javascript:void(0);',styles:{position:'absolute',
zIndex:-1,
border:'none',
top:0,
left:0,
'filter':'alpha(opacity=0)'
},width:'100%',height:'100%'})).inject(document.body);
  var mpdSize = {
  loginBuy:{width:570},  
  };
   
  $extend(MiniPassport,{
   
  show:function(from,options){
  var handle = this.handle = from;
  options = this.options = options ||{};
   
  var remoteURL = options.remoteURL||(handle?handle.get('href'):false);
   
  var act ="login";
   
  act = remoteURL.match(/-([^-]*?)\.html/)[1];
   
   
  if(miniPassportDialog.style.display=='none'){
  var _styles = {display:'block'};
   
  miniPassportDialog.setStyles(_styles);
  }
  miniPassportDialog.getElement('.dialog-content').empty();
   
   
  var fxValue = mpdSize[act];
  fxValue.opacity = 1;  
  miniPassportDialog.setStyles(fxValue).amongTo(window);
   
   
   
  // if(window.ie6) remoteURL=(remoteURL.substring(0,4)=='http')?remoteURL:remoteURL;

  $pick(this.request,{cancel:$empty}).cancel();
  this.request = new Request.HTML({update:miniPassportDialog.getElement('.dialog-content').set('html','&nbsp;&nbsp;正在加载...'),onComplete:function(){
  MiniPassport.onload.call(MiniPassport);
  }}).get(remoteURL,$H({mini_passport:1}));
   
  },
  hide:function(chain){
   
  miniPassportDialog.getElement('.dialog-content').empty();