using System;
using System.Configuration;
using System.Text.RegularExpressions;

namespace Microsoft.Samples.AspNet.Validators
{
    internal class UsingRegexStringValidator
    {
        private static void Main(string[] args)
        {

            String e_mail = "2313.0";
            Console.Out.WriteLine( isValidString(e_mail));
        }



        public static  bool isValidString(String e_mail){
            string expr = "[0-9]*.[0-9]*";

            Match isMatch =Regex.Match(e_mail, expr);

            return isMatch.Success;
        }  
    }
}