using System;

public class Demo

{

    public static void Main()

    {

        string mystr, rev;

        mystr = "Tom";

        rev= " ";

        Console.WriteLine("String is {0}",mystr);

        int len;

        len=mystr.Length-1;

        while (len>=0)

        {

            rev = rev+mystr[len];

            len--;

        }

        Console.WriteLine("Reversed string is {0}", rev);

        Console.ReadLine();

    }

}

​