validate email address
public bool IsValid(string emailaddress) { private const string EmailRegEx = @"^[w!#$%&'*+-/=?^_`{|}~]+(.[w!#$%&'*+-/=?^_`{|}~]+)*" + "@" + @"((([w]+([-w]*[w]+)*.)+[a-zA-Z]+)|" + @"((([01]?[0-9]{1,2}|2[0-4][0-9]|25[0-5]).){3}[01]?[0-9]{1,2}|2[0-4][0-9]|25[0-5]))z"; return new Regex(EmailRegEx, RegexOptions.None).Match(emailaddress).Success; }