using System.Text.RegularExpressions; public static class Validate { public static bool IsDomain(string value) { if (string.IsNullOrEmpty(value)) return false; Regex url = new Regex(@"^[\w\-_]+((\.[\w\-_]+)+([a-z]))?$", RegexOptions.Compiled | RegexOptions.IgnoreCase); return url.IsMatch(value); } }