Simple Code Keeps Crashing IE8 but works in FF

Hi everyone,

I'm not a genius at javascript, so can anyone explain why in Firefox, the following code works, but in IE7 it won't open the popup windows, and even worse, in IE8, half of my computer shuts down.

Thanks

function submitfrm(){
		name=document.helpform.help.value;
		if(name=="bookmark.html"){
			bookmark("http://www.allpostalsupplies.com", "AllPostalSupplies.com")
		}else{
		document.helpform.action=name;
		document.helpform.submit();
		document.helpform.reset();
		}
		}
		function bookmark(url,title){
			if ((navigator.appName == "Microsoft Internet Explorer") && (parseInt(navigator.appVersion) >= 4)) {
				window.external.AddFavorite(url,title);
			} else if (navigator.appName == "Netscape") {
				window.sidebar.addPanel(title,url,"");
			} else {
				alert("Press CTRL-D (Netscape) or CTRL-T (Opera) to bookmark");
			}
			document.helpform.reset();
		}	

Code (markup):

Form code:

<form id="helpform" name="helpform">
	<select name="help">
		<option value="" onclick="window.open('https://www.allpostalsupplies.com/ask-a-question.html','As Us a Question','scrollbars=yes,left=1,top=1,width=425,height=570')">Ask Us a Question</option>
		<option value="" onclick="window.open('https://www.allpostalsupplies.com/let-us-call.html','Have Us Call You','scrollbars=yes,left=1,top=1,width=425,height=500')">Have Us Call You</option>
		<option value="mailto:contact@allpostalsupplies.com">E-mail Us</option>
		<option value="bookmark.html">Bookmark This Site</option>
	</select> 
<input name="submit" type="button" value="Submit" onclick="submitfrm(this.form)" />
</form>

Code (markup):