function DialogOverlay() {
	// Assign instance variables
	this.overlay = $('overlay2').hide();
	this.dialog = $('dialog2').hide();

	// Hide the overlay when clicked. Ignore clicks on the dialog.
	Event.observe(this.overlay, 'click', this.hide.bindAsEventListener(this));
	Event.observe(this.dialog, 'click',  function(event) { Event.stop(event) });
	this.dialog.hide();
}
 
DialogOverlay.prototype.show = function() {
	new Effect.Appear(this.overlay, { duration: 0.5,  to: 0.8 });
	this.dialog.show();
	return this;
};
DialogOverlay.prototype.hide = function(event) {
	this.dialog.hide();
	this.overlay.hide();
	return this;
};