Wow - I got to say that the support in here is really awesome. Thank
you very much (although the postet sproc is not working, too).

<ranting>
Maybe I´m too much involved in using MSSQL so far. Everything is a lot
easier, faster to develop and easier to debug. I tried the
IBExpert-GUI, which *sorry* s_c_s and I tried Flamerobin, which
miserably fails compared to IBExpert. The best GUI I found was "EMS
SQL Manager for Interbase/Firebird", and it s_c_s, too: SET TERM is
not supported correctly, debugging a sproc leads in not in useful
error-messages, no way to develop fast and stable procedures.

And until now I was only trying some easy things. What will be, when I
try to port my 300+ lines sprocs from msssql to firebird? No offense,
but this is just not practicable for me.
</ranting>

So I think I´ll switch back. Thanks for trying to help anyway. Again:
awesome support in here :)