$(function () {
$('header').css({backgroundPosition: '50% 5%'});
$('header').mousemove(function(e){
    $(this).css({backgroundPosition: "-" + e.pageX/30 + "px" + " -" + e.pageY/22 + "px"});
});
$('header').mouseleave(function(){
    $(this).css({backgroundPosition: '50% 5%'});
});
});