I have a contest running at my website and have everything going fine except that I'd like to be able to validate the email when they sign up for the newsletter.

The newsletter sign-up is ran through the usual cgi form thingy and have that if they don't enter an email address they get sent to the "missed email" page but would really like to be able to check for common typo's.

I tried adding a Javascript into it and it didn't work at all... any ideas?