Not a silly question...but definitely a duplicate question. What you need is the SUBCATEGORIES LIKE YAHOO 2.0 MOD, which is located in the LINKS MODIFICATION FORUM.
Search for SUBCATEGORIES LIKE YAHOO in the LINKS MODIFICATION FORUM, via the forum's search form.
Regards,
------------------ Eliot Lee.... Former Handle: Eliot * Check Resource Center * Search Forums * Thinking out of the box (codes) is not only fun, but effective.