well, combo boxes and command buttons have nothing to do with each other, so
i don't quite get the segue... at any rate, to create a combo box control on
a form, the quickest and simplest way is to build it with the combo box
wizard. if you're not familiar with combo boxes, suggest you read up on them
in Help, then walk through the wizard, and post back if you run into any
specific problems.
hth