list categories and pages in search results?

Hi,

I’m working on building my own theme in which I have a search box. It only returns posts containing the search term. Is there a way without using one of the search plugins to tell wordpress to search categories and pages too?

I tried the search unleashed plugin but it just includes the option to search pages.

I’d like to be able to type in ‘codeigniter’ and have it show the codeigniter category even though there are no posts in it yet. If I knew where to edit the code I could add something to tell the user this category is empty right below the listing. Then if there are posts it should show all posts in that category.

Thanks for any point in the right direction.