Validating user Input

Here is a brief example that shows how to validate user input

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication4
{
    class Program
    {
        /// 

        /// This program uses the quadratic equation
        /// to produce a a prime number
        /// with a seed of any integer between 1 and 41
        /// The main purpose is to show you how you 
        /// can validate the users input.
        /// the TryParse makes sure that the number 
        /// is an integer without crashing the program
        /// the while loop keeps repeating the user prompt
        /// until they enter an integer in the valid range
        /// Steve Conger 11/1/2012
        /// 
       
        static void Main(string[] args)
        {
            Program p = new Program();
            p.HowToTestUserEntry();
            Console.ReadKey();
        }

        private void HowToTestUserEntry()
        {
            //you want them to enter an integer between 1 and 41
            //declare the variabe to test
            int number = 0;
            //create a loop that won't stop until 
            //they enter a proper number
            while (number < 1 || number > 41)
            {
                Console.WriteLine("Enter an integer between 1 and 41");
                //if it parses correctly it will assign the integer to the
                //variable number, otherwise it returns false
                bool entry = int.TryParse(Console.ReadLine(), out number);
                //if it is false or the number is not between
                //1 and 41 prompt them to enter a correct number
                if (!entry || number < 1 || number > 41)
                {
                    Console.WriteLine("Please make sure you entered an integer between 1 and 41");
                }//end if
            }//end while

            //this equation is a mathematical oddity
            //that returns 41 prime numbers in sequence
            //for numbers between 1 and 41
            int prime = number * number - number + 41;
            Console.WriteLine("The prime number is {0}", prime);
        }
    }
}