[jQuery] [Validate plugin] Force default value into box?

Hi all,
I'm using Jorn's validation plugin and I was wondering if it was
possible to force a value into a box when it doesn't validate. For
example, a box requiring digits could be set to 0 if the validator picks
up an error (and the message still shown, the user can then change the
value if they wish)
Is this possible?
Regards,
Michael Price