System.Windows.Forms.MessageBoxManager.UnhookWindowsHookEx C# (CSharp) Method

        private static extern int UnhookWindowsHookEx(IntPtr idHook);

 public static void Unregister()
 {
     if (MessageBoxManager.hHook != IntPtr.Zero)
     {
         MessageBoxManager.UnhookWindowsHookEx(MessageBoxManager.hHook);
         MessageBoxManager.hHook = IntPtr.Zero;
     }
 }