#region RegexMailpublic bool RegexMail(string email){    try    {        string pattern = @"^[a-z][a-z|0-9|]*([_][a-z|0-9]+)*([.][a-z|" +        @"0-9]+([_][a-z|0-9]+)*)?@[a-z][a-z|0-9|]*\.([a-z]" +        @"[a-z|0-9]*(\.[a-z][a-z|0-9]*)?)$";        System.Text.RegularExpressions.Match match = Regex.Match(email, pattern, RegexOptions.IgnoreCase);        if (match.Success)        {            return true;        }        else        {            return false;        }    }    catch (Exception ex)    {        return false;    }}#endregion