//获得控件的位置
function getAbsolutePosition(obj)
{
position = new Object();
position.x = 0;
position.y = 0;
var tempobj = obj;
    while(tempobj!=null && tempobj!=document.body)
    {
        if(window.navigator.userAgent.indexOf("MSIE")!=-1)
        {
            position.x += tempobj.offsetLeft+4;
            position.y += tempobj.offsetTop+5;
        }
        else 
  {
   if(window.navigator.userAgent.indexOf("Firefox")!=-1)
         {
            position.x += tempobj.offsetLeft;
            position.y += tempobj.offsetTop;
         } else  {
      position.x += tempobj.offsetLeft+4;
            position.y += tempobj.offsetTop+5;
     }
   }
        tempobj = tempobj.offsetParent
    }
return position;
}