window.addEvent('load', function(){
   var zoomTip = new Tips($$('.ngis-browse-product-image'), {
      className: 'custom',
      initialize:function(){
         this.fx = new Fx.Style(this.toolTip, 'opacity', {duration: 800, wait: false}).set(0);
      },
      onShow: function(toolTip) {
         this.fx.start(1);
      },
      onHide: function(toolTip) {
         this.fx.start(0);
      }
   });
});