gtk_window_set_position (GTK_WINDOW (window), GTK_WIN_POS_CENTER);
gtk_window_set_default_size (GTK_WINDOW (window), 450, 250);
gtk_window_set_position (GTK_WINDOW (window), GTK_WIN_POS_CENTER);
gtk_window_set_default_size (GTK_WINDOW (window), 450, 250);