function jscss(a,o,c)
{
  switch (a){
    case 'add':
      if(!jscss('check',o,c)){o.className+=o.className?' '+c:c;}
    break;
    case 'remove':
      var rep=o.className.match(' '+c)?' '+c:c;
      o.className=o.className.replace(rep,'');
    break;
  }
}
function rollover()
{
	if(!document.getElementById || !document.createTextNode){return;}
	var n=document.getElementById('horiz-nav');
	if(!n){return;}
	var lis=n.getElementsByTagName('li');
	for (var i=0;i<lis.length;i++)
	{
		lis[i].onmouseover=function()
		{
			jscss('add',this,'over');
		}
		lis[i].onmouseout=function()
		{
			jscss('remove',this,'over');
		}
	}
}
window.onload=rollover;