var scrollSpeed = 50;
var direction = 'h';
var current = 0;	 
var init_scroller;

function bgscroll()
{ 
   current -= 1;     
   $('div.clouds').css("backgroundPosition", (direction == 'h') ? current+"px 0" : "0 " + current+"px");    
}

function stop_scroller()
{
	if (init_scroller)
	{
		clearInterval(init_scroller);
		init_scroller = null;
	}
}
	
function start_scroller()
{
	if (!init_scroller)
		init_scroller = setInterval("bgscroll()", scrollSpeed); 	
}