var scrollSpeed = 70;
			var step = 1;
			var current = 0;
			var imageHeight = 500;
			var headerHeight = 235;
			var restartPosition = -(imageHeight - headerHeight);			
			function scrollBg(){		
				current -= step;			
				if (current == restartPosition){
					current = 0;
				}				
				$('#scroll').css("background-position","0 "+current+"px");
			}
			var init = setInterval("scrollBg()", scrollSpeed);