I have used the call back function for phone no validation from here.
function valid_phone_number_or_empty($value)
{
$value = trim($value);
if ($value == '') {
return TRUE;
}
else
{
if (preg_match('/^\(?[0-9]{3}\)?[-. ]?[0-9]{3}[-. ]?[0-9]{4}$/', $value))
{
return preg_replace('/^\(?([0-9]{3})\)?[-. ]?([0-9]{3})[-. ]?([0-9]{4})$/', '($1) $2-$3', $value);
}
else
{
return FALSE;
}
}
}
But now the problem is it doesn't accept phone-no from european countries and other parts of world which are 11 to 13 digits. Can anyone provide me with any other validation for that's universal for all countries?