//document.onmousemove = mouseMove;
window.onscroll = mouseMove;
function mouseMove(ev){
        //ev           = ev || window.event;
        //var mousePos = mouseCoords(ev);
	theTop = document.documentElement.scrollTop;
       // document.getElementById('quadrato').style.left = mousePos.x+5;
	document.getElementById('layer1').style.top = theTop + 'px' ;
	document.getElementById('layer2').style.top = theTop + 'px' ;
	document.getElementById('layer3').style.top = theTop + 'px' ;
	document.getElementById('layer4').style.top = theTop + 'px' ;


}

function mouseCoords(ev){
        if(ev.pageX || ev.pageY){
               return {x:ev.pageX, y:ev.pageY};
        }
        return {
               x:ev.clientX + document.body.scrollLeft - document.body.clientLeft,
               y:ev.clientY + document.body.scrollTop  - document.body.clientTop
        };
}