ISSUE:
How to grab items from the query string?
SOLUTION:
SharePoint 2007 uses QueryString heavily, in order to display data.
If you have access to the SharePoint Server, under the 12\TEMPLATE\LAYOUTS\1033, you will find a bunch of JS files that are used by SharePoint. Most importantly, within this folder, you will find the following file: INIT.JS
which contains a function called : GetUrlKeyValue(QueryStringName)
Moreover, you can use the same function name under SharePoint 2003, however, you must reference the ows.js file instead.
EXAMPLE:
1. Make reference to the JS File
2. And then simply call the function
<script type="text/javascript" language="javascript" src="/_layouts/1033/init.js"></script>
<script>
var x = GetUrlKeyValue("Source");
alert(x);