Hi Dorin

>How did you created, via ISQL ?

I used IBExpert (as you had suggested previously) to create the thing and the DDL was from it.

it turns out that I am supposed to use it like this as per suggestions

>>SELECT (SELECT bOSDrAmt FROM OSAcctDrAmt(s.bDrAmt, uf.bDr, uf.bCr)) AS bBalDr, ....

Thanks again for your help, with it I was able to create the first FireBird stored procedure, seriously.