var isDOM = (document.getElementById ? true : false); 
var isIE4 = ((document.all && !isDOM) ? true : false);
var isNS4 = (document.layers ? true : false);
function getRef(id)
{
 if (isDOM) return document.getElementById(id);
 if (isIE4) return document.all[id];
 if (isNS4) return document.layers[id];
}
function getStyle(id) {
 return (isNS4? getRef(id) : getRef(id).style);
} 
function getTop(e)
{
 var nTop=e.offsetTop;
 var ePar=e.offsetParent;
 while (ePar!=null){
  nTop+=ePar.offsetTop;
  ePar=ePar.offsetParent;
  }
 return nTop;
}
function getLeft(e)
{
 var nLeft=e.offsetLeft;
 var ePar=e.offsetParent;
 while (ePar!=null){
  nLeft+=ePar.offsetLeft;
  ePar=ePar.offsetParent;
  }
 return nLeft;
}