public static bool IsValidMobileNo(string MobileNo)
{
const string regPattern = @"^(130|131|132|133|134|135|136|137|138|139)\d{8}$";
return Regex.IsMatch(MobileNo, regPattern);
}
{
const string regPattern = @"^(130|131|132|133|134|135|136|137|138|139)\d{8}$";
return Regex.IsMatch(MobileNo, regPattern);
}