I have a DHTML menu then creates dropdown menus on our company website. It has been working fine for at least a year and now all of a sudden the drop downs no longer work in IE. Can anyone tell me if they see anything wrong with this code, because I am stumped.

the website is http://radsafety.com

it works fine in firefox, but now IE is all screwed.

any help would be appreciated.

the javascript is as follows and is in the file global.js:

function startList() {
if (document.all&&document.getElementById) {
navRoot = document.getElementById("nav");
for (i=0; i<navRoot.childNodes.length; i++) {
node = navRoot.childNodes[i];
if (node.nodeName=="LI") {
node.onmouseover=function() {
this.className+=" over";
}
node.onmouseout=function() {
this.className=this.className.replace(" over", "");
}
}
}
}
}
window.onload=startList();

and the menu is included in the page header:
HTML Code:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
	<head>
		<meta http-equiv="content-type" content="text/html">
		<meta name="Description" content="Radiation Safety & Control Services' experienced staff provide consulting services,Calibration Services, Leak Testing, Instrumentation repair and waste management.">
		<meta name="Keywords" content="Radiation Safety Officer, radiation safety, safety training, DOT radiation safety , RSO, radioactive, radioactivity, radiation,Dirty bomb, radiological emergency, health physics, nuclear, radiation protection, decommissioning, decontamination, transportation, licensing, certified health physicist, CHP, NRRPT, Fred Straccia, Jay Tarzia, Eric Darios,leak testing,ion track,instrument calibration,repair services,radon,radon mitigation, Radiation Service Organization, RSCS Inc, New England, Stratham, New Hampshire,NH">
		<meta name="robots" content="index,follow">

		<title><?php echo $title; ?></title>
		<script type="text/javascript" src="scripts/global.js">
		</script>
		<script type="text/javascript" src="scripts/style.js">
		</script>
	</head>
	<body>
		<!--Begin Header-->
		<table width="750px" id="header">
		<tr>
			<td width="90px"align="left"><img src="images/logo_anim_small.gif" style="margin:5px 0px 3px 10px;" alt="Radiation Safety &amp; Control Services" /></td>
		</tr>
		</table>
		<!--End Header-->
		<!--Start navMenu-->

		<div id="menu">
		<ul class="sea" id="nav">
			<li class="sea" id="subnav"><a href="index.php">Home</a></li>
			<li class="sea" id="subnav"><a href="aboutus.php">About RSCS</a></li>
			<li class="sea" id="subnav"><a href="consulting.php">Consulting</a></li>
			<li class="sea" id="subnav"><a href="calibration.php">Calibration</a></li>
			<li class="sea" id="subnav"><a href="#">Lab Services</a>
				<ul class="subsea" id="navLab">
					<li class="subsea"><a href="leak_testing.php">Leak Testing</a></li>
					<li class="subsea"><a href="radon.php">Radon</a></li>
					<li class="subsea"><a href="repair.php">Repairs</a></li>
			   </ul>
			</li>
			<li class="sea" id="subnav"><a href="links.php">Links</a></li>
			<li class="sea" id="subnav"><a href="products.php">Products</a>
				<ul class="subsea" id="navProducts">
					<li class="subsea"><a href="sts.php">STS Products</a>
					<li class="subsea"><a href="dosimeters.php">Dosimeters</a>
						<ul id="sidemenu">
							<li class="sidemenu"><a href="dmc2000.php">MGP DMC2000</a></li>
							<li class="sidemenu"><a href="global.php">Global</a></li>
							<li class="sidemenu"><a href="at.php">ArrowTech</a></li>
						</ul>
					</li>
					<li class="subsea"><a href="homeland.php">Homeland Security</a></li>
					<li class="subsea"><a href="leaktests.php">Leaktests</a></li>
					<li class="subsea"><a href="instruments.php">Instrumentation</a>
						<ul id="sidemenu">
							<li class="sidemenu"><a href="nukesafeguard.php">Nuke Safeguard</a></li>
							<li class="sidemenu"><a href="nd-2rid.php">NDS ND-2RID</a></li>
							<li class="sidemenu"><a href="nd-200id.php">NDS ND-200ID</a></li>
							<li class="sidemenu"><a href="nd-200pc.php">NDS ND-200PC</a></li>
							<li class="sidemenu"><a href="nd-500p.php">NDS ND-500P</a></li>
							<li class="sidemenu"><a href="nd-2000.php">NDS ND-2000</a></li>
							<li class="sidemenu"><a href="r200.php">RAM R-200</a></li>
						</ul>
					</li>
					<li class="subsea"><a href="software.php">Software</a>
					</li>
					<li class="subsea"><a href="cart/">Online Store</a>
					</li>
				</ul>
			</li>
			<li class="sea" id="subnav"><a href="staffing.php">Staffing</a></li>
			<li class="sea" id="subnav"><a href="training.php">Training</a>
				<ul class="subsea" id="navTraining">
					<li class="subsea"><a href="#" onclick="popup('arso.html')"><!--onclick="popup()"-->ARSO Outline</a></li>
					<li class="subsea"><a href="#" onclick="popup('rso.html')">RSO Outline</a></li>
					<li class="subsea"><a href="#" onclick="popup('chem.html')">CHEM Outline</a></li>
					<li class="subsea"><a href="trainingform.php">Sign Up</a></li>
				</ul>
  			</li>
		</ul>
		</div>