Anyone see any reason why this doesn't run in Mozilla? (OK in IE, but if you're seizure prone don't run it). I get a "Error: outer.style has no properties - Line: 61". I'm thinking IE is returning an interface that supports both HTML and XML DOM, while Moz is returning one that only supports XML. Else I'm overlooking something.

Thanks.

Code:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
	"http://www.w3.org/TR/html4/loose.dtd">
			
<html lang="en">
<head>
	<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
	<title>BW Test Page</title>
<style type="text/css" media="screen" title="Default">
div {
	border: none;
	padding: 10px;
	margin: 0px;
}

.container {
	border: 3px solid blue;
	padding: 0px;
}

.black {
	color: black;
	background-color: black;
}

.white {
	color: white;
	background-color: white;
}
</style>
<script type="text/javascript">
var inner;
var outer;
var iSize = 0;
var oSize = 10;

function bw() {
	var vdiv = document.getElementById('mdiv');
	//vdiv.style.borderColor = "red";
	outer = vdiv.firstChild;
	inner = outer;
	
	oSize--;
	if (oSize == 0) { 
		oSize = 10; 
		//get the innermost div
		while ( inner.firstChild ) {
			if ( inner.className == "black" ) {
				inner.className = "white";
			} else {
				inner.className = "black";
			}
			inner = inner.firstChild;
		}
	} else {
		//get the innermost div
		while ( inner.firstChild ) {
			inner = inner.firstChild;
		}
	}
	iSize = 10 - oSize;
	
	outer.style.padding = oSize + "px";
	inner.style.padding = iSize + "px";
	
	setTimeout("bw()", 1);
	
}
</script>
</head>

<body>

<div id="mdiv" class="container">
	<div class="black">
		<div class="white">
			<div class="black">
				<div class="white">
					<div class="black">
						<div class="white">
							<div class="black">
								<div class="white" style="padding: 0px;"></div>
							</div>
						</div>
					</div>
				</div>
			</div>
		</div>
	</div>
</div>

<div onclick="bw();">Click</div>

</body>
</html>