var div_id = null;

		function move_the_mouse(e)
		{
			if (div_id == null)
				return;

			var x, y, div = document.getElementById(div_id);
			
			if (!e)
			{
				x = event.x;
				y = event.y;
			} else {
				x = e.pageX;
				y = e.pageY;
			}
			
			div.style.left = x + 5 +"px";
			div.style.top = y + 5 +"px";
		}
		
		document.onmousemove = move_the_mouse;


-----------------


<a onmouseover="P7_autoLayers(0,'preview0m'); div_id = 'preview0m';" onMouseOut="P7_autoLayers(0); div_id = null;" >