Alex, > Since you have a server socket, "sd" should be a value returned by accept(). Very big OOPS! Thanks for the help and sorry for the stupidity. This is a university work and I find the call model system of the teacher very inapropiate. Anyway, that's no excuse. Thanks again. Salutacions, Pere ---- __o Ultima Ratio Regum 2:343/108.91 ----- _`\<;_ mailto:pere@casal.upc.es PGP key available --- (_)/ (_) http://casal.upc.es/~pere/