alt_tabpage(void)
{
    tabpage_T	*tp;

    // Use the next tab page if possible.
    if (curtab->tp_next != NULL)
	return curtab->tp_next;

    // Find the last but one tab page.
    for (tp = first_tabpage; tp->tp_next != curtab; tp = tp->tp_next)
	;
    return tp;
}
alt_tabpage(void)
{
    tabpage_T	*tp;

     
    if (curtab->tp_next != NULL)
	return curtab->tp_next;

     
    for (tp = first_tabpage; tp->tp_next != curtab; tp = tp->tp_next)
	;
    return tp;
}