Batch gpg encryption : prompt

[Yard, John]

I am doing scriptewd/batch gpg encryption , and I am
getting the following repeated prompts: 

It is NOT certain that the key belongs to the person named
in the user ID.  If you *really* know what you are doing,
you may answer the next question with yes.

Use this key anyway? (y/N) y

How do I eliminate these prompts? This script will be automatically run.

JYard