Regular Expressions C#

//Microsoft Public License (Ms-PL)
//http://c4fdevkit.codeplex.com/license
using System;
using System.Collections.Generic;
using System.Text;
using System.Text.RegularExpressions;
namespace C4F.DevKit.WebServices
{
    /// 
    /// Provides useful methods like conversion methods.
    /// 

    public static class Utility
    {
        /// 
        /// Validates the exchange code
        /// 

        /// Exchange code to be validated
        /// True, if exchange code is valid
        public static bool ValidateExchangeCode(string exchangeCode)
        {
            if (String.IsNullOrEmpty(exchangeCode))
                return false;
            return Regex.IsMatch(exchangeCode, "^[0-9]{3}$");
        }
    }
}