Precision -Pimpy needs help

[Pimpya]

using System;

public class Pimpy
{
   public static void Main(String []a)
   {
       Double d=100.123456789123456789123456789123456789;
       Console.Writeline("{0}",d); 
   }
} 

I'd like the output to be decimally correct as defined, but only 16 digits after the dot is output.

Someone please help me..

Thanks

-Pimpy-