if you are looking how to set the users homepage this is a text link that sets it (if someone could tell me how to change that for when the page loads that would be great )
<SPAN onClick="this.style.behavior='url(#default#homepage)';this.setHomePage('http://www.wsabstract.com');">Click here to make wsabstract ur home page</SPAN>
To my knowledge, you cannot read what the user's homepage is, unless they are using IE and you use ActiveX and search through their registry, but they'll (hopefully) get big scary alerts saying why they shouldn't allow the script to run.
You can redirect them to their homepage though:
if (!window.home) window.home = function() { location.href = 'about:home' };