$(document).ready(function() {

var x=-1000, 
    y=0,
    rate=0,
    maxspeed=5;
var backdrop = $('.backdrop');

$('.direction', backdrop).mousemove(function(e){
    var $this = $(this);
    var left = $this.is('.left');
	
    if (left ){
        var w = $this.width();
        rate = (0.3);
    }
    else{
        var w = $this.width();
        rate = (-0.3);
    }
});

backdrop.hover(
    
	function(){
		
        var scroller = setInterval( moveBackdrop, 30 );
        $(this).data('scroller', scroller);

    },
    function(){
        var scroller = $(this).data('scroller');
        clearInterval( scroller );
    }

);   

function moveBackdrop(){
    x += maxspeed * rate;
    var newpos = x+'px '+y+'px';
    backdrop.css('background-position',newpos);
}





});