GOOD GRIEF!!!
This was NOT a daft question and I have to say that the replies from those that should ...and state that they are in a position to help are very ...very sad!
Good luck with the interview. A suit that fits and does not look as if it's just out of the bag. A white shirt (that fits), with the newness ironed out. A plain..ish tie, smart shoes and you are there. Dress for the job you want. Look like a pilot (without the wings!) and your half way there. Your fist 5 seconds are the most important!