Listing 8-2 extracted from chapter Interoperability between .NET and native code/COM/ COM+

Listing 8-1<     > Listing 8-3

This listing can be compiled with the command line:
csc.exe /target:exe Example_8_2.cs
Errors: 0 Warnings: 0

using System.Runtime.InteropServices;
class Program {
   [DllImport("Kernel32.dll", EntryPoint = "Beep")]
   public static extern bool MyBeep( uint iFreq, uint iDuration );
   static void Main() {
      bool b = MyBeep(100, 100);
   }
}