I saw that there is a build-in code for regular expression. How do I set it?
I'm not sure what you mean. Do you mean the email XSL templates? They can be set on the FBA Site Configuration page, found in Site Settings.
I meant the checking of user input. I want to check if the user entered a valid e-mail address.
Oh - we did use to have a regular expression validation for the email address - but there always seemed to be the odd email address that was valid but did not pass the regular expression test - so the check was removed. We only check that the field is present now.
I figured. I couldn't find anything in the code that's setting the expression. Anyway, I'm adding a RegularExpressionValidator field in the CreatUserStepTemplate right now. Maybe you could add this to your future patches if you want to. Thanks!