USE OF CURSORS IN ECPG

Hi,
I'm just starded using ecpg and I have some problem with cursors.

I wrote this lines

exec sql begin declare section;
    char query[500];
    int CodImpianto;
    int Cod1;
    int Cod2;
    char Descr[100];
exec sql end declare section;
strcpy(query, "select ............");

exec sql connect db;

sub1()
{
    exec sql prepare stmtunimpianto from :query;
    exec sql declare CUR_UNIMPIANTO cursor for stmtunimpianto;
    .
    .
    .

    exec sql open CUR_UNIMPIANTO using :CodImpianto;
    exec sql fetch CUR_UNIMPIANTO into :CodImpianto, :Descr;
    .
    .

    exec sql close CUR_UNIMPIANTO;
    exec sql execute StmtUpdImpianti using :Cod1, :Descr, :Cod2;
    exec sql commit;
}

I call this routine a lot of time.
If I rem the commit all works fine but if I execute the commit the cursor was deleted and I receive some errors.

At open cursor : sqlca.sqlcode = -230 Invalid statement namei in line ......
at fetch           : NOTICE : PerformPortalFetch: portal "cur_unimpianto" not found

Please could anyone help me ?

thanks

regards
Maurizio Cauci
DREAMTECH di Cauci Maurizio
Via Ronchetti, 2 - 21013 Gallarate (VA)
www.dreamtech-it.com