function getTopPosition(obj)
{
	var p=0;
	while(obj)
	{
		p += obj.offsetTop;
		obj = obj.offsetParent;
	}
	return p;
}
function getScrollTopPosition()
{
	return window.pageYOffset ? window.pageYOffset : (document.documentElement ? document.documentElement.scrollTop : document.body.scrollTop);
}
function getNextNode(obj)
{
	while((obj = obj.nextSibling)!=null) if(obj.nodeType==1) return obj;
	return null;
}
function getFirstChild(obj)
{
	obj=obj.firstChild;
	do{
		if(obj.nodeType==1) return obj;
	}while((obj = obj.nextSibling)!=null);
	return null;
}