using System;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        string[] partNumbers= { "99", "9.47", 

                              "9.99", "99.99", 

                              "0919-2893-1256" };

      Regex rgx = new Regex(@"^(\d{2})+\.\d{2}$");

      foreach (string partNumber in partNumbers)

         Console.WriteLine("{0} {1} a valid part number.", 

                           partNumber, 

                           rgx.IsMatch(partNumber) ? "is" : "is not");

    }

    private static readonly Regex Pattern = new Regex("{(.+?)}", RegexOptions.Compiled);

​

}