JavaScript 控制层拖动及背景透明

//floatbox.js
function getElement(aID)
{
  return (document.getElementById) ? document.getElementById(aID)
                                   : document.all[aID];
}
function getAllElement()
{
  return (document.getElementsByTagName) ? document.getElementsByTagName("*")
           : document.all;
}
function getParentElement(elm)
{
 return (elm.parentElement) ? elm.parentElement : elm.parentNode
}
var Drag={
        "obj":null,
 "init":function(a, aRoot){
   a.οnmοusedοwn=Drag.start;
   a.root = aRoot;
   if(isNaN(parseInt(a.root.style.left)))a.root.style.left="0px";
   if(isNaN(parseInt(a.root.style.top)))a.root.style.top="0px";
   a.root.onDragStart=new Function();
   a.root.onDragEnd=new Function();
   a.root.onDrag=new Function();
  },
 "start":function(a){ 
   var b=Drag.obj=this;
   a=Drag.fixE(a);
   var c=parseInt(b.root.style.top);
   var d=parseInt(b.root.style.left);
   b.root.onDragStart(d,c,a.clientX,a.clientY);
   b.lastMouseX=a.clientX;
   b.lastMouseY=a.clientY;
   document.οnmοusemοve=Drag.drag;
   document.οnmοuseup=Drag.end;
   return false;
  }, 
 "drag":function(a){
   a=Drag.fixE(a);
   var b=Drag.obj;
   var c=a.clientY;
   var d=a.clientX;
   var e=parseInt(b.root.style.top);
   var f=parseInt(b.root.style.left);
   var h,g;
   h=f+d-b.lastMouseX;
   g=e+c-b.lastMouseY;
   b.root.style.left=h+"px";
   b.root.style.top=g+"px";   
   b.lastMouseX=d;
   b.lastMouseY=c;
   b.root.onDrag(h,g,a.clientX,a.clientY);
   return false;
  },
 "end":function(){   
   document.οnmοusemοve=null;
   document.οnmοuseup=null;
   Drag.obj.root.onDragEnd(parseInt(Drag.obj.root.style.left),parseInt(Drag.obj.root.style.top));
   Drag.obj=null;
  },
 "fixE":function(a){
   if(typeof a=="undefined")a=window.event;
   if(typeof a.layerX=="undefined")a.layerX=a.offsetX;
   if(typeof a.layerY=="undefined")a.layerY=a.offsetY;
   return a;
  }
};

function addLightboxMarkup() {

 bod     = document.getElementsByTagName('body')[0];

 overlay    = document.createElement('div');
 overlay.id   = 'overlay';

 bod.appendChild(overlay);
}
function hideSelect(visibility){
 selects = document.getElementsByTagName('select');
 for(i = 0; i < selects.length; i++) {
  selects[i].style.visibility = visibility;
 }
}
function preIE(height, overflow){
  bod = document.getElementsByTagName('body')[0];
  bod.style.height = height;
  bod.style.overflow = overflow;
 
  htm = document.getElementsByTagName('html')[0];
  htm.style.height = height;
  htm.style.overflow = overflow;
}
function getRange() {
      var top     = document.documentElement.scrollTop;
      var left    = document.documentElement.scrollLeft;
      var height  = document.documentElement.clientHeight;
      var width   = document.documentElement.clientWidth;

      if (top==0 && left==0 && height==0 && width==0) {
        top     = document.body.scrollTop;
        left    = document.body.scrollLeft;
        height  = document.body.clientHeight;
        width   = document.body.clientWidth;
      }

      return  {top:top  ,left:left ,height:height ,width:width } ;
}
function showBox(e){
 if(typeof e=="undefined")e=window.event;
//获取 原贴信息
 var lobj=e.srcElement;
 var rel=lobj.getAttribute("rel");
 var relobj=getElement(rel);
 var rbody = relobj.innerHTML;
 rbody=rbody.replace(/<.*>/gi,"");
 //rbody=rbody.replace(/<[^>]*>/gi,"");
 if(rbody.length>55){
  rbody = rbody.substring(0,55) + "...";
 }
 getElement("quotebody").innerHTML=rbody;
 getElement("quote").value=rel;

 hideSelect("hidden");
 overlay.style.display="block";
 WfloatBox.style.display="block";

 var range=getRange();
 WfloatBox.style.top=(range.top+WfloatBox.oy) +"px";
 WfloatBox.style.left=(range.left+WfloatBox.ox) +"px";

 //window.οnscrοll=onbodyscroll;
}

function onbodyscroll(){
 var range=getRange();
 WfloatBox.style.top=(range.top+WfloatBox.oy) +"px";
 WfloatBox.style.left=(range.left+WfloatBox.ox) +"px";
}

function closeBox(){
 hideSelect("visible");
 overlay.style.display="none";
 WfloatBox.style.display="none";
}

function initbox(){ 
 var range=getRange();
 WfloatBox=getElement("floatBox");
 WfloatBox.ox=(range.width-400)/2;
 WfloatBox.oy=(range.height-300)/2;
 
 //加载拖动事件
 Drag.init(getElement("draghead"),WfloatBox);

 WfloatBox.onDragEnd=function(x,y){
  WfloatBox.ox=x-getRange().left;
  WfloatBox.oy=y-getRange().top;
 }

 addLightboxMarkup();

 overlay.style.height=document.body.clientHeight;

 var all=getAllElement();
 var l=all.length;
 for(var i=0;i  var o=all[i];
  if(o.className=="lbOn")
  {
   o.attachEvent("onclick",showBox);
  }
 }
}
window.οnlοad=initbox;