Use do while loop to find the square root of a number in CSharp

using System;//from  w w  w. jav a2s .c o  m

public class MainClass {
   public static void Main( ) {
      double epsilon   = 1.0e-9;
      double guess    = 11.0;
      double result   = 0.0;

      double value = 2;

      result = ((value / guess) + guess) / 2; 

      do {
            Console.WriteLine( "Guess Value  = {0}", guess  );
            Console.WriteLine( "Result Value = {0}", result );
            guess = result;
            result = ((value / guess) + guess) / 2;
      } while( Math.Abs(result - guess) > epsilon );
      Console.WriteLine("The approx sqrt of {0} is {1}", value, result );
    }
}