Customised validation possible?

[josh909]

I've been using WFF for a while now on a number of sites but am now
wondering if it's possible to specify customised validation? For
example can I specify:

- that the 'email' field must contain an '@' symbol?
- that the 'phone number' field can only contain numbers?

If WFF can't do this, is anyone aware of a workaround?

Thanks in advance.