Phone no. Is not valid in dial up connection

I m trying to connet a dial up connectiom through my mobile. It is right my phone is detected when i connect it,but when i enter wvdial command at the terminal it shows three errors.
1. The username specified is not valid.
2.the password is not valid
3. The phone number specified is not valid.
Where is the problem? I write these in wvdial.conf file like this-
username = aa
password = bb
phone number = *99#
i hv tried it both on fedora 7 as well as ubuntu 8.04
plz tell me wat to do?