gistfile1.js

var Slider=new Class({
	Implements:Chain,
	initialize: function (element){
		this.element = $(element);
	},
	slide: function(prop, pos0, pos1){
		this.element.set('tween', {
			duration : 2000,
			transition : Fx.Transitions.Cubic.easeInOut
		});
		this.element.tween(prop, [pos0, pos1]);
	}
});

function init()
{
	var mySlider=new Slider($('quad'));
	mySlider.chain(
		mySlider.slide('left', 0, 400),
		mySlider.slide('top', 0, 200),
		mySlider.slide('left', 400, 0),
		mySlider.slide('top', 200, 0)
	);

	mySlider.callChain();
	mySlider.callChain().delay(2000,mySlider);
}

window.addEvent('domready', init);