static gboolean on_switch_page (PsppireDataEditor *de, GtkNotebookPage *p, gint pagenum, gpointer data);
static void on_select_range (PsppireDataEditor *de);
static gboolean on_switch_page (PsppireDataEditor *de, GtkNotebookPage *p, gint pagenum, gpointer data);
static void on_select_range (PsppireDataEditor *de);