var movementStrength = 25;
var height = movementStrength / jQuery(window).height();
var width = movementStrength / jQuery(window).width();
jQuery("body").mousemove(function(e){
          var pageX = e.pageX - (jQuery(window).width() / 2);
          var pageY = e.pageY - (jQuery(window).height() / 2);
          var newvalueX = width * pageX * -1 - 25;
          var newvalueY = height * pageY * -1 - 50;
          jQuery('#hero').css("left", newvalueX+"px     ");
          jQuery('#hero').css("top", newvalueY+"px");
        });

ALL RIGHTS RESERVED - MARIO D'ANELLI