Almost working - need a little help

[Chris]

I have a script that will navigate back and foreward using a form. The
files it navigates are named: bg1.html, bg2.html, bg3.html, etc.

This is happening in a frameset, where my BACK and FORWARD buttons are
in one frame, and the content pages are in another (main).

I can get read the current page location in the frame "main", but it
is not working (getpagenumber)- it should give the current page
number, and use that number to tell the rest of the script where Back
and Foreward is. The current page is "bg1.html"

My script is below, followed by the form that will use it. Any help or
advice would be appreciated:

<script language="JavaScript">
<!--
function getpagenumber() {
var otherpage = parent.main.location.href;
var pagenumber =
otherpage.substring(otherpage.length-3,otherpage.length);
return pagenumber - 0;
}

function goForward() {
var page = getpagenumber();
if (page < 100)
parent.main.location.href = 'bg' + pad(page + 1,3) + '.html';
}
function goBackward() {
var page = getpagenumber();
if (page > 1)
parent.main.location.href = 'bg' + pad(page - 1,3) + '.html';
}
function pad(number,length) {
var str = '' + number;
while (str.length < length)
str = '0' + str;
return str;
}
//--></script>




<form>
<input type="button" value="Back" onClick="goBackward()">
<input type="button" value="Forward" onClick="goForward()">
</form>