1. You must disable the "Enable python" checkbox in the exporting window if you do not need the python. But if you need, you must enable "Copy python26.dll to export directory".
2. First, add button object and go to event sheet and double click on the button object and create "on button click" event.Then add "go to layout" action from application.
3. Add combo box item and in the event sheet add your level numbers. Then add "on button click" action from the button object and add the level changer action then in the text box write "Combobox.SelectedLine" and when player is selected line 2 the application will go to layout 2.