function ShowOverlay(div_id)
{
	
	var div = document.getElementById(div_id);
	
	div.style.display = "block";
	
	div.style.position ="absolute";
	
	//div.style.left = 258 + "px";
	
	//div.style.top = 443 + "px";
	
	div.style.left = (document.body.scrollLeft + (document.body.clientWidth - div.clientWidth) / 2) + "px";
	
	div.style.top = (document.body.scrollTop + (document.body.clientHeight - div.clientHeight) / 2) + "px";

}

function CloseOverLay(div_id)
{
	
	var div = document.getElementById(div_id);
	
	div.style.display = "none";

}