Installing Dp4.0 On Osx Panther, Problems encountered Options

[_Gary Leo_]

Hi all,
I have a Powerbook G4 which is running on Panther. I am a music arranger by profession and i was trying to install a music software known as the Digital Performer version 4.0. The installation needs me to key in the key code provided by the sofware maker so that i can run the application. I am currently unable to complete the process cos after keying the code, the Key Code window appears again. And it happens every time i try to key in the code again. Can anyone please kindly advice me on what is going on? Thanks