Gerhard,

> The RES_CODE will return (testet), but
> how can I get this RES-CODE value in my application?

I would did the next:
1. I would add SUSPEND in your code.
....
....

> begin
> RES_CODE = "1";
> end

SUSPEND; /*Add*/

> END;

2. Next, I would use a tib_cursor as:

MyCursor: SQL: 'select RES_CODE from INV_IN(?INV_IN)'

and the delphi code:

function TForm1.recall_value:string
begin
With MyCursor do begin
if not prepared then prepare;
parambyname('INV_IN').asString:='your_string';
first;
if not eof then
result:=fieldbyname('RES_CODE').asString
else result:='';
end
end;

Usually, I avoid tib_storedproc and use tib_cursor, tiq_query .... after
add suspend in SP.

Luiz.