Detecting IE6 using jQuery.support

While it’s good practice to check for feature support rather then user agent, there’s no simple way to check for something like support of a css property using JavaScript. I recommend you either follow the above posters suggestion of using conditional comments or use jQuery.browser. A simple implementation (not validated for performance or bugs) could look like this:

if ($.browser.msie && $.browser.version.substr(0,1)<7) {
  // search for selectors you want to add hover behavior to
  $('.jshover').hover(
    function() {
      $(this).addClass('over');
    },
    function() {
      $(this).removeClass('over');
    }
}

In your markup, add the .jshover class to any element you want hover css effects on. In your css, add rules like this:

ul li:hover, ul li.over { rules here }