Event.observe(window, 'load', function() {
   if (!window.XMLHttpRequest) {
      // IE6, older browsers       //new HoverBehavior('li');
      $$('ul.hover li').each( function(e) {
         Event.observe(e, 'mouseover', function() {
         Element.addClassName(e, 'hover');
         });
         Event.observe(e, 'mouseout', function() {
         Element.removeClassName(e, 'hover');
         });
      });
   }
});