When you say "not working", what exactly do you mean? When you enter something that does not match the mask, does it simply not treat it as an error? Or does it redisplay the page with no error message?
Do you have other validations for the same page that are working?
Its not at all treating it as an error, its successfully going to next page. no validation is happening.
Joined: Feb 15, 2005
If you change the validation rule to "required", does that validation work? The reason I'm asking is that there are a number of problems that can occur to prevent validation from working. We need to know whether it's a problem with validation in general, or specifically with the mask rule.