Email validator

Hi,

I am trying to validate, if the email address entered by user is of the following pattern {[a-z][0-9]._}@{[a-z][0-9]._}.[a-z]}

When I try to create a user defined validator with function contains and above pattern, it doesn't work.

It always returns true, that mean even if user enter just name, it return true.

I want to validate this at the form itself not hit backend for validate. Please suggest.

Thanks

Prashil