find_dialog_focus - Searches the dialog for the object which has the input
focus. Allegro game programming library.
int find_dialog_focus(DIALOG *dialog);
Searches the dialog for the object which has the input focus, returning an index
or -1 if the focus is not set. This is useful if you are calling do_dialog()
several times in a row and want to leave the focus in the same place it was
when the dialog was last displayed, as you can call do_dialog(dlg,