var XPosition = 20;
var YPosition = 20;
var MouseOverGrafik;

Event.observe(
	window,
	'load',
	function() {
		MouseOverGrafik = $('MouseOverGrafikCSS');
		
		Event.observe(
			$$('body')[0], 
			'mousemove',
			function(e) {
				x = Event.pointerX(e);
				y = Event.pointerY(e);
				MouseOverGrafik.style.visibility = 'visible';
				MouseOverGrafik.style.left = x + XPosition + 'px';
				MouseOverGrafik.style.top = y + YPosition + 'px';
			}
		);
	}
);