var moveRight  = function() {
	$('scroller').tween('left', '-325px');
}
 
var moveLeft  = function() {
	$('scroller').tween('left', '0px');
}
 
window.addEvent('domready', function() {
	$('leftarrow').addEvent('click', moveLeft);
	$('rightarrow').addEvent('click', moveRight);
});