kppp problem with fc5

[S. Cesaretti]

Hello,
I'm using fedora core 5 and I should use kppp to make one dial up 
connection.
I'm using the internal modem of my laptop computer with slmodem driver and
I'm sure that it works well.
but when I try to establish one dial up connection
the answer from the kppp is "NO CARRIER".
I'm quite sure that I should add the atx3 parameter before that it sends the 
string atdt with the number, but
I don't know how can I add it and if I can add it.
what would be the problem?
How can I solve that problem?