Rob,
By "choosebox" perhaps you mean "checkbox." Besides the fact that this does not seem to be a Perl question, you have to also elaborate where/how you are working. Are you making a Windows native program with Perl as the backend (in which case you have to use some gui-making technology such as Tk) or are you talking about a web-based program driven by Perl (in which case, you need to read up on HTML).
Once again, look at the basic tutorials on this site; there are many.
Most such questions will be answered.
Good luck.
Update: added links to tutes.