[C#][.NET]プログラムの二重起動しないようにする Prevent multiple instances of a given app

[STAThread]

static void Main() 
{
   using(Mutex mutex = new Mutex(false, "Global\\" + appGuid))
   {
      if(!mutex.WaitOne(0, false))
      {
         MessageBox.Show("Instance already running");
         return;
      }

      Application.Run(new Form1());
   }
}

private static string appGuid = "c0a76b5a-12ab-45c5-b9d9-d693faa6e7b9";

参考URL
　http://stackoverflow.com/questions/93989/prevent-multiple-instances-of-a-given-app-in-net