> I use Firebird 2.1 on Xp sp2.

Very well

> I would like to know if is possible to use CREATE FUNCTION with a IN
> parameter and the result is a table, in this case many cursor of WITH
> RECURSIVE.
>
> This is the code that I use in MsSQL 2005.

Giuliano, Firebird is NOT MSSQL. Firebird even is not Interbase ;)
Learn its PSQL language, please, before making any assumption.

Regards,
Vlad