using system;
using system.threading;

class app {
   public static void main() {
      console.writeline("checking for status updates every 2 seconds.");
      console.writeline("   (hit enter to termiante the sample)");
      timer timer = new timer(new timercallback(checkstatus), null, 0, 2000);

      console.write("press enter to close window…");
      console.read();
   }

   // the callback methods signature must match that of a system.threading.timercallback
   // delegate (it takes an object parameter and returns void)
   static void checkstatus(object state) {
      console.writeline("checking status.");
      // …
   }
}