window.addEvent('domready', function(){ var thetip = new Tips($$('.thetip'), { initialize:function(){ this.fx = new Fx.Style(this.toolTip, 'opacity', {duration: 500, wait: false}).set(0); }, onShow: function(toolTip) { this.fx.start(1); }, onHide: function(toolTip) { this.fx.start(0); } }); });