Code
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<head>
<title> Fragment</title>
<style type="text/css">
A.topLinks {font-weight:bold}
.Borders {font-weight:bold}
</style>
<script type="text/javascript">
function modRule()
{
if (!document.styleSheets) return;
var thecss = new Array();
if (document.styleSheets[0].cssRules) // Standards Compliant
{
thecss = document.styleSheets[0].cssRules;
}
else
{
thecss = document.styleSheets[0].rules; // IE
}
for (i=0;i<thecss.length;i++)
{
if ((thecss[i].selectorText.toLowerCase()=='a.toplinks') || (thecss[i].selectorText.toLowerCase()=='.borders'))
{
thecss[i].style.cssText="font-weight:normal; color:red";
}
}
}
</script>
</head>
<body>
<a href="#" class="topLinks" onclick="modRule();return false;">click here</a>
<div class="Borders"> hello world. <span style="color:blue">All of your bases are belong to us.</span> </div>
</body>
</html>