Hero(or maybe Android)Touch dialpad problem

thor

I have an HTC hero and have come across a problem that I need a bit of help with. I think it is an android problem though. I was trying to pay a bill using my mobile and got to the stage where I had to tap in password info via the touch dialpad. I swiftly realised that even though each key had a number with a 2 or 3 letters accompanying it, it was only the number that could be selected. I read the manual but did not find any reference telling me how to type in the letters. I am assuming this is possible but need somebody to show me how it is done.