dependent drop down lists

Hi guys
Kindly help me in coming up with dependent drop down lists in excel 2007 and how do u link them such that if u pick on an item on a list e.g vehicle model A then u realize you picked the wrong one and u actually wanted vehicle B, when u click on vehicle B it clears out your previous selection.

thank u

Have you tried under the developer tab, insert - form controls - combo box?