Regular Expression restricting a sepecific domain in Email

[Sendhil]

Hi All,
We are using the following regular expression to accept
emails from all domain except 'wipro.com'
This works prefectly fine in a console app using the RegEx
class - match method.
The expression is <exp>\w+([-+.]\w+)*@(?!wipro.com)</exp>

Why doesn't this work with ASP.NET Regular Expression
Validator control

Thanks in Advance

Regards,
Sendhil.