can't read output variable calling a PROCEDURE in ORACLE

[dodonovi]

hi..

i'm using ZeosLib 6.6.4-stable in Borland Builder 5
my connection with Oracle DB is OK (via VPN) the SELECT
queries are good.

i'm tryng to CALL a Stored Procedure on ORACLE 10g2
the procedure is like this:
procedure NAME( par1 in number, par2 out varchar2 ) ....

i try a lot of solution with TZQuery and TZSQLProcessor
i made the parameter run time or design time..

for example a "no error" running solution is this:

SQL= "CALL NAME( 1, :xx)"

where i have defined a parameter like "xx",
DataType= ftString,
ParamType= ptOutput

i made ExecSQL() or Open() commands
and my parameter XX is void
i have no return FIELDS..

i think the query CALL was running ok, but i don't how read the out
value par2 (xx)
can someone help me ? do you need more details ??

thanks Davide.