function validate_phone($number) {
	$number = preg_replace('/[^\d]/', '', $number);
	return preg_match('/^(0(2|3|4|7|8))?\d{8}$/', $number) 
		|| preg_match('/^1(3|8)00\d{6}$/', $number)
		|| preg_match('/^13\d{4}$/', $number);
}