Validate cvv number

Hi all,

I found this code for cvv number validation:

if (MODULE_PAYMENT_CC17_COLLECT_CVV == 'True')  {
      $js .= '    var cc_cvv = document.checkout_payment.cc_cvv.value;' . "\n";
    }

My problem is that even though the validation works for minimum of a 3 digit cvv number my customers can still use the space bar to trick the validation. can anybody help with an idea of changing this so that the three digits must be numerical numbers 1 - 9

Tried this but it only works for other characters not spaces from the space bar:```
}
$js .= ' if (isNaN(cc_cvv)){' . "\n" .
' error_message = error_message + "' . MODULE_PAYMENT_CC17_TEXT_JS_CC17_NOTNUMBER . '";' . "\n" .
' error = 1;' . "\n" .
' }' . "\n" ;

So it isn't quite right

What payment module are you using?

I am using slightly modified versions of the standard credit card modules which store card data for manual processing by my staff.

The modifications are to include a small surcharge for card use and encryption of the card number before storage in the databse.