[Vlasenko Fedor]

$code = filter_input(INPUT_GET, 'code', FILTER_VALIDATE_INT);
if (false === empty($code)) 
{
	$_SESSION['code'] = $code;
}
else //$code 0, Null, false
{
	$code = 769;
}

$code = filter_input(INPUT_GET, 'code', FILTER_VALIDATE_INT);
if (empty($code))//$code 0, Null, false
{
	$code = 769;
}
else 
{
	$_SESSION['code'] = $code;
}