gtk_text_buffer_get_end_iter (ov->buffer, &end_iter);
mark = gtk_text_buffer_create_mark (ov->buffer, NULL, &end_iter, TRUE);
/* Read in the next lot of text */
gtk_text_buffer_get_end_iter (ov->buffer, &end_iter);
mark = gtk_text_buffer_create_mark (ov->buffer, NULL, &end_iter, TRUE);
/* Read in the next lot of text */