All the more reason to do it in Perl. You simply have not provided us with enough criteria, not to mention that this is a Perl community, and while a lot of us code in Java, most of us are going to say either use Perl ... or use the right tool for the job. It you are truly dealing with a simple graphical interface, then ANY language which provides the ability to do so is the right tool for this job. It's really up to your personal preferences from there.

UPDATE:
Just wanted to point out the a web page form could be considered a simple graphical interface ... i assume that you are talking about Tk vs. Java applets.

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)