anyone know this problem?
tib_storedproc work fine with output params

sp.parambyname('par1').asstring:=var1;
sp.execproc;
var2:=sp.parambyname('par1').asstring;is OK
var2:=sp.fieldbyname('par1').asstring;is OK

tibo_storedproc not work

sp.parambyname('par1').asstring:=var1;
sp.execproc;
var2:=sp.parambyname('par1').asstring;param 'par1' not found
var2:=sp.fieldbyname('par1').asstring;field 'par1' not found

can anyone help my?