What is wrong with the script below?

It is the HTML used for a password window on my site. At present people have to type the password and then click on a button. However, with many other web sites (such as hotmail) you can instead press return or enter if you should desire. I would like to give visitors to my site the opportuntiy the press return or enter.

the script/HTML coding is:

<HTML>
<HEAD>
<TITLE>Gate Keeper</TITLE>

<SCRIPT LANGUAGE="JavaScript">
<!--- Hide from tired old browsers that should be put to pasture.

////////////////////////////////////////////////////////////////////
/// Get your very own Gate Keeper from Professional Web Design ///
/// http://junior.apk.net/~jbarta/weblinks/gate_keeper/ ///
////////////////////////////////////////////////////////////////////

function goForit() {
var location;
var password;
password=this.document.testform.inputbox.value
location=password + ".html"
fetch(location)
theKeeper=window.close()
}

function fetch(location) {
var root;
if (opener.closed) {
root=window.open('','theKeepersGopher','toolbar=yes,location=yes,status=yes,menubar=yes,scrollbars=yes,resizable=yes,copyhistory=no');
root.location.href = location;
} else {
opener.location.href = location;
}
}

// End hiding --->
</SCRIPT>

</HEAD>

<BODY BACKGROUND="keeper.gif">

<TABLE BORDER=0 CELLPADDING=0 CELLSPACING=0 WIDTH=100%>
<TR>
<TD ROWSPAN=2 WIDTH=50%>
&nbsp;&nbsp;

<TD WIDTH=50% ALIGN=CENTER VALIGN=MIDDLE>
<FONT FACE="ARIAL" SIZE=2><B>Hold on there buddy. You'll need a password to get in here. We're tryin' to keep out the riff-raff.</B></FONT><BR>
&nbsp;

<TR>
<TD WIDTH=50% ALIGN=CENTER VALIGN=BOTTOM>
<CENTER>
<FORM NAME="testform">
<INPUT TYPE="text" NAME="inputbox" VALUE="" size=20>
<INPUT TYPE="button" NAME="button" Value="Submit Password" onClick="goForit(this.form)">



<!--- You can remove the following link if you want.
I just added it to satisfy my own selfish interests.
Just remove the following line and this comment. --->
<P><FONT SIZE=1 FACE="COMIC SANS MS"><A HREF="http://junior.apk.net/~jbarta/weblinks/gate_keeper/" TARGET="_blank"><B>Gate Keeper</B></A></FONT>



</FORM>
</CENTER>


</TABLE>

</BODY>

</HTML>


I am not too good at manipulating HTML, but perhaps someone can help?

I look forward to your comments,

MATT.