GUI shell script for Linux

Hi,
I want to write shell script file that have a GUI with multiple input box for user entry , i mean multiple input box in one dialog ( window) not one window for each entry , i tried kdialog , and zenity , i didnt find a way to have multiple input box in one window with zenity and kdialog.
Anybody know a script language for do that or know a way to do that with zenity or kdialog?!
here is what i want to do:
a register form for users:
Username: -inputbox
Password: -inputbox
confirm password: -inputbox
...
P.S: i want that for redhat based linux , like redhat Enterprise , centos and fedora!
Regards.