function show_submenu(item)
{
    var elem = item.parentNode;
    if (elem.className == 'menu-active')
	{
	    /*elem.className = 'menu-inactive'*/
	    return true
	}
    var elems = elem.parentNode.childNodes;
    for(var i=0; i<elems.length; i++)
	{
	    if (elems[i].className == 'menu-active')
		elems[i].className = 'menu-inactive'
	}
    elem.className = 'menu-active'
    return false
}