I wouldn't recommend using iframes, but you could do it like this: http://bonrouge.com/demos/current_iframe.htm
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd"><html>
<head>
<title>Show current with iframe</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<style type="text/css">
* {
margin:0;
padding:0;
}
body {
background-color:white;
}
#menu {
float:left;
margin:20px;
}
a:link, a:visited {
color:navy;
}
a:hover {
color:white;
background:red;
}
a:active {
color:gray;
}
a.current {
color:white;
background:navy;
}
iframe {
width:800px;
height:500px;
}
</style>
<script type="text/javascript">
function current(menu) {
var atags=document.getElementById(menu).getElementsByTagName('a');
for (i=0; i<atags.length; i++) {
atags[i].onclick=function() {
for (j=0; j<atags.length; j++) {
atags[j].className=atags[j].className.replace(new RegExp("current\\b"), "");
}
this.className+=" current";
}
}
}
window.onload=function() {current('menu')}
</script>
</head>
<body>
<ul id="menu">
<li><a href="http://google.com" target="theiframe">Google</a></li>
<li><a href="http://bonrouge.com" target="theiframe">bonrouge</a></li>
<li><a href="http://php.net" target="theiframe">php manual</a></li>
</ul>
<iframe name="theiframe"></iframe>
</body>
</html>