Preview = new Class.create();
Preview.prototype = {

	initialize: function() {
		this.currentId = "";
	},

	Execute: function(id) {
		if (id == this.currentId) {
			new Effect.Fade(id,{ from:1.0,to:0,duration:0.5});
			this.currentId = "";
			return;
		} else {
			if (this.currentId != "") {
				new Effect.Fade(this.currentId,{ from:1.0,to:0,duration:0.5});
			}
		}

		new Effect.Appear(id,{ from:0.0,to:1,duration:0.5});
		this.currentId = id;
	}

};