function beginDrag(elementToDrag,event)
{
  var deltaX=event.clientX-parseInt(elementToDrag.style.left);
  var deltaY=event.clientY-parseInt(elementToDrag.style.top);
 
if(document.addEventListener)
{
  document.addEventListener("mousemove",moveHandler,true);
  document.addEventListener("mouseup",upHandler,true);
}
else if(document.attachEvent)
{
  document.attachEvent("onmousemove",moveHandler);
  document.attachEvent("onmouseup",upHandler);
 
}
 
  if(event.stopPropagation)   event.stopPropagation();
  else event.cancelBubble=true;
  if(event.preventDefault)  event.preventDefault();
  else event.returnValue=false;
 
  function moveHandler(e) 
  {
　　if (!e) e=window.event; //如果是IE的事件对象，那么就用window.event
　　//全局属性，否则就用DOM二级标准的Event对象。
    elementToDrag.style.left=(event.clientX-deltaX)+"px";
    elementToDrag.style.top=(event.clientY-deltaY)+"px";
   
     if(event.stopPropagation)   event.stopPropagation();
    else event.cancelBubble=true;
   
  }
 
  function upHandler(
e)
  {
       if(document.removeEventListener)
    {
      document.removeEventListener("mouseup",upHandler,true);
      document.removeEventListener("mousemove",moveHandler,true);}
      else
    {
      document.detachEvent("onmouseup",upHandler);
      document.detachEvent("onmousemove",moveHandler);}
    }
      if(event.stopPropagation)   event.stopPropagation();
    else event.cancelBubble=true;
   
  }