Joypad not working with doom3 demo on PC

Hi all,

I have downloaded the doom 3 demo for my PC but I cannot see any option
in the settings to change the controller from keyboard to joy pad.

I tried hitting buttons on the joy pad in the Controls menu but this
didn't work - it only seems to want keyboard input.

The joy pad works fine with other games.

Is this an issue with just the demo or will I not be able to use my joy
pad with the full game too?

Thanks,

John