auto-install script hangs Internet Explorer 7

[Anil]

I want to bring to your attention the Javascript code in the article
http://java.sun.com/developer/technicalArticles/JavaLP/javawebstart/AutoInstall.html
It breaks in IE7.0.
The browser hangs and has to shut down.
I would appreciate any help.
thanks,
Anil

----------------------------------------------

<script language="javascript"><!---
var detect = navigator.userAgent.toLowerCase();
var windowsIE = (checkPlatform("msie") && checkPlatform("win"));
var launchTID;

var thisLocation =
location.href.substring(0,location.href.lastIndexOf('/')+1);


function launchApp() {
if (windowsIE) {
document.write("<OBJECT

CODEBASE=http://java.sun.com/update/1.5.0/jinstall-1_5_0_09-windows-i586.cab

CLASSID=clsid:5852F5ED-8BF4-11D4-A245-0080C6F74284 HEIGHT=0
WIDTH=0>");
document.write("<PARAM NAME=app VALUE=" + thisLocation +

"juwoDemos_files/juwo.jnlp>");

document.write("<PARAM NAME=back VALUE=true>");
document.write("</OBJECT>");
} else {
if (navigator.mimeTypes && navigator.mimeTypes.length) {
if (!webstartVersionCheck("1.5")) {
// Java Web Start not installed; open browser window to install site

window.open("http://jdl.sun.com/webapps/getjava/BrowserRedirect?locale=en&host=java.com",

"needdownload");
}
// Spin quietly, waiting to launch the app from the original window
launchTID = setInterval('launchJNLP(thisLocation +

"juwoDemos_files/juwo.jnlp")', 200);
}
}
}
function webstartVersionCheck(versionString) {
navigator.plugins.refresh(true);
// First, determine if Webstart is available
if (navigator.mimeTypes['application/x-java-jnlp-file']) {
// Next, check for appropriate version family
for (var i = 0; i < navigator.mimeTypes.length; ++i) {
pluginType = navigator.mimeTypes.type;
if (pluginType == "application/x-java-applet;version=" +
versionString) {
return true;

}
}
}
}
function launchJNLP(app) {
if (webstartVersionCheck("1.5")) {
clearInterval(launchTID);
window.location = app;
}
}

function checkPlatform(string) {
place = detect.indexOf(string) + 1;
thestring = string;
return place;
}
--></script>