csshover.htc

<attach event="ondocumentready" handler="parseStylesheets" />
<script language="JScript">

var CSSBuffer, doc = window.document;

function parseStylesheets() {
  var rules, sheet, sheets = doc.styleSheets;
  var bufferIndex = sheets.length;	
  var head = doc.getElementsByTagName('head')[0];
  var buffer = doc.createElement('style');
  buffer.setAttribute('media', 'screen');
  buffer.setAttribute('type', 'text/css');
  head.appendChild(buffer);
  CSSBuffer = sheets[bufferIndex];
  for(var i=0; i<sheets.length -1; i++) {
    sheet = sheets[i];
      if(!sheet.media || sheet.media == 'screen') {
         rules = sheet.rules;
         for(var j=0; j<rules.length; j++) {
            parseCSSRule(rules[j]);
         }
      }
   }
}

function parseCSSRule(rule) {
  var select = rule.selectorText, style = rule.style.cssText;
  if(!select || !style || select.indexOf(':hover') < 0) return;
  var newSelect = select.replace(/\:hover/g, '.onHover');
  CSSBuffer.addRule(newSelect, style);
  var affected = select.replace(/\:hover.*$/g, '');
  var elements = getElementsBySelect(affected);
  for(var i=0; i<elements.length; i++) {
    if(elements[i].nodeName == 'A') continue;
    new HoverElement(elements[i]);
  }
}

function HoverElement(element) {
  if(element.isHoverElement) return;
  element.isHoverElement = true;
  element.attachEvent('onmouseover', 
   function() { element.className += ' onHover'; });
  element.attachEvent('onmouseout', 
  function() { element.className = element.className.replace(/onHover/g, ''); });
}


function getElementsBySelect(rule) {
  var nodeList = [doc], sets = rule.split(' ');
   for(var i=0; i<sets.length; i++) {
      nodeList = domFinder.filterNodes(sets[i], nodeList);
   }	
   return nodeList;
}

var domFinder = {
	findNodes:function(tag, docs) {
		var res, nodes = [];
		for(var i=0; i<docs.length; i++) {
			res = docs[i].getElementsByTagName(tag);
			for(var j=0; j<res.length; j++) nodes[nodes.length] = res[j];
		}	return nodes;
	},

	filterNodes:function(select, docs) {
		var filtered = [], nodes,rule,atr,s = (/#|\./).exec(select);
		if(!s) return this.findNodes(select, docs);
		nodes = this.findNodes((rule = select.split(s))[0], docs);
		atr = (s == '#')? 'id':'className';
		for(var i=0; i<nodes.length; i++) {
			if(new RegExp('(^|\\s)' +  rule[1] + '(\\s|$)').exec(nodes[i][atr]))
				filtered[filtered.length] = nodes[i];
		}	return filtered;
	}
}
</script>