production problem on calculated fields

Hello,
I have a routine da calculetes two field that on development all works fine but on production does not work!!.
The method is fired on a combofield onchange.
This is the method :

$up = 0;
$tp = 0;
$d1 = strtotime({data_f});
$d2 = strtotime({data_o});
$dif = $d1-$d2;
$gg = ceil($dif/86400); // giorni di noleggio
{giorni} = $gg;
//-----------------------------
$error_test = $gg < ‘1’; // Error test
$error_message = ‘La data di check in deve essere piu grande della data di check out.’; // Error message
if ($error_test)
{
sc_error_message($error_message);
sc_error_exit();
}
else
{
//-----------------------------
$att = {id_att};
sc_lookup(dataset,“SELECT id_iva from attivita WHERE id_att = $att”);
$civa = {dataset[0][0]}; // codice aliquota iva

sc_lookup(dataset,“select aliquota from iva where id = $civa”);
$alq = (({dataset[0][0]}/100)+1); // aliquota iva calcolo iva

$grp = {id_grp};
$ir = {id_rat};
sc_lookup(dataset,“SELECT T1,T2,T3 FROM Tariffe WHERE attiva = ‘Y’ and id_grp = $grp and id_rat = ‘$ir’”);
$t1 = {dataset[0][0]};
$t2 = {dataset[0][1]};
$t3 = {dataset[0][2]};

if ($gg <3)
{$up= $t1;}

if ($gg >2 and $gg <5)
{$up= $t2;}

if ($gg >4)
{$up= $t3;}

$tp = ($up*$gg)$alq; // totale noleggio iva inclusa
$up = $up
$alq; // costo giornaliero iva inclusa
{u_price} = $up;
{t_price} = $tp;
}

As i said it does not show the result in the fields {u_price} and {t_price} but in development it’s OK.

Please can anyone help
Thanks
Maurizio C.