title: Unable to get the window title
body: <p>I am unable to get the window title of the Skype. The following code returns an empty string:</p>
  
  <pre><code>std::wstring get_window_title(HWND hwnd)
  {
    wchar_t window_title[256];
    SendMessageW(hwnd, WM_GETTEXT, (WPARAM)256, (LPARAM)window_title);
    return window_title;
  }
  </code></pre>
  
  <p>Window's handle is valid.</p>
  
  <p>Am I using this function incorrectly?</p>
  
  <p>Thanks in advance.</p>