jQuery Background Panning

backgroundpanning.js

$('.panbg').mousemove(function(e){
    //Let's find the midpoints of the screen
    var midpointX = $(window).width()/2
    var midpointY = $(window).height()/2
    //Now the pointer's deviation as a percentage.
    var mousePosX = ((e.pageX-midpointX)/$(window).width())*100;
    var mousePosY = ((e.pageY-midpointY)/$(window).height())*100;
    //Let's dilute it by a factor of 40
    var xPos = mousePosX/40 + 50;
    var yPos = mousePosY/40 + 50;
    //Finally, let's move the background :)
    $('.panbg').css('backgroundPosition', xPos+'% '+ yPos+'%');
});