Making a tabbed search box?

I was reading this tutorial on making a tabbed search box but I was confused as to how I was supposed to implement the actual code that does the searching. The tutorial is here

Can anyone help me out?

This would be easier to implement if you already had a search function on your website, which I will assume you do not. The actual searching is done via a server-side languageā€¦ PHP, ASP, one of those languages. For an example of how to create this in PHP, you can check out this tutorial -