Thank you marcel, now is working and never mind for the new entry in the taskbar.

One more stupid question; when i close the mainwindow the child remains open. I have created a destructor for the mainWindow like this:

Qt Code:
  1. MainWindow::~MainWindow()
  2. {
  3. if(gameViewer)
  4. gameViewer->close();
  5. }
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but doesn't work.

Regards