This is not going to help you for tomorrow but JIC you want to know for future reference, I have the most fantastic book on job applications and interviews.

Philip Garside (2005) The Secrets of Getting a Job, the script for your next job interview. Second edition (2005). Hyland House.

I have always performed well at interviews but my poor DH constantly sells himself short. This book has will hopefully really help him next time (he is yet to test out what it says IRL).

What Tegan and Briggsy's Girl said was great. Try to relax, be yourself and be happy. Good luck from me too. Let us know how you go.