I wish you the very best of luck!
Be confident...Remember, THEY are lucky to be interviewing YOU.
Be sure to let them know specifically how you will be a valuable asset to their company.
Do a bit of 'homework' on the company...What new products do they have coming out? What have been their successes? Be able to comment on these things so they see you have an interest.
I will PM you with more!!
Go get 'em!