title: The name 'Marshal' does not exist in the current context
body: <p>I got the code below from the bitmapmixer sample (DirectShow.NET) and i tried to reimplement it. The original sample works fine. In my version when I try to compile i get errors.</p>
  
  <pre><code>private void AddHandlers()
      {
          // Add handlers for VMR purpose
          this.Paint += new PaintEventHandler(Form1_Paint); // for WM_PAINT
          this.Resize += new EventHandler(Form1_ResizeMove); // for WM_SIZE
          this.Move += new EventHandler(Form1_ResizeMove); // for WM_MOVE
          SystemEvents.DisplaySettingsChanged += new EventHandler(SystemEvents_DisplaySettingsChanged); // for WM_DISPLAYCHANGE
          handlersAdded = true;
      }
  
      private void RemoveHandlers()
      {
          // remove handlers when they are no more needed
          handlersAdded = false;
          this.Paint -= new PaintEventHandler(Form1_Paint);
          this.Resize -= new EventHandler(Form1_ResizeMove);
          this.Move -= new EventHandler(Form1_ResizeMove);
          SystemEvents.DisplaySettingsChanged -= new EventHandler(SystemEvents_DisplaySettingsChanged);
      }
  </code></pre>
  
  <hr>
  
  <hr>
  
  <p>ERRORs</p>
  
  <hr>
  
  <p>Error   1   The name 'Marshal' does not exist in the current context        Form1.cs<br>
  Error   2   The name 'Marshal' does not exist in the current context        Form1.cs<br>
  Error   3   The name 'Form1_ResizeMove' does not exist in the current context   Form1.cs<br>
  Error   4   The name 'Form1_Paint' does not exist in the current context        Form1.cs<br>
  Error   5   The name 'Form1_ResizeMove' does not exist in the current context   Form1.cs<br>
  Error   6   The name 'Form1_ResizeMove' does not exist in the current context   Form1.cs<br>
  Error   7   The name 'SystemEvents_DisplaySettingsChanged' does not exist in the current context    Form1.cs<br>
  Error   10  The name 'Form1_ResizeMove' does not exist in the current context           Form1.cs<br>
  Error   11  The name 'SystemEvents_DisplaySettingsChanged' does not exist in the current context    Form1.cs    </p>
  
  <hr>
  
  <p>Any help is appreciated.</p>
  
  <p>Thanks.</p>