Window.onDomReady(function(){
Window.disableImageCache (); 
$S('.dasmenu li a').each(function(el) { 
var effect = el.effect('background-position', {duration: 500, wait: false, transition: fx.Transitions.circOut, fps: 50}).set(-300);
el.addEvent('mouseover', effect.goTo.pass(0, effect)).addEvent('mouseout', effect.goTo.pass(-300, effect));
});
});