title: WindowFromPoint doesn't work correctly on 64bit .NET Framework
body: <p>I wrote the easy test program by C# and .NET 4.0. </p>
  
  <pre><code>[DllImport("user32.dll")]
  static extern IntPtr WindowFromPoint(int xPoint, int yPoint);
  
  Point pt = MousePosition;
  IntPtr w = WindowFromPoint(pt.X, pt.Y);
  </code></pre>
  
  <p>If this builts as 32bit, it works. But if it builds as 64bit, an unrelated window handle will return. Are there a solution or alternatives?</p>