title: Gtk hiding window on it's callback
body: <p>I have a function that I want to hide on pressing a button. I've read that I can define multiple callbacks on a signal and they will be called in the same order as defined. So I wanted to execute two functions on button press and I wanted one of them to hide window that contains this button. I tried to do it like this:</p>
  
  <pre><code>g_signal_connect(btn_confirm, "clicked", G_CALLBACK(function_that_does_stuff), NULL);
  g_signal_connect(btn_confirm, "clicked", G_CALLBACK(kill_window), add_conn_win);
  ...
  void kill_window ( GtkWidget* wdgt, GtkWidget* win )
  {
    gtk_widget_hide_all(win);
  }
  </code></pre>
  
  <p>But this isn't working. Window's still there. Can someone tell me how to do that?</p>