function centerWindow(layer) {
			document.getElementById(layer).style.display='inline';
			var xMax = document.body.clientWidth, yMax = document.body.clientHeight;
					
			var xOffset = (xMax-200)/2+10, yOffset = (yMax-150)/2+10;
			var divMenu = 'inline';
			divMenu.top = yOffset;
			divMenu.left = xOffset;
	}
				
	function HideHint(layer) {
			var obj;
			obj = document.getElementById(layer);
			obj.style.display = "none";
	}