function ShowMenu(obj)
{
    HideAll();
	if(document.layers) document.layers[obj].visibility = "show";
	if(document.all && !document.getElementById) document.all[obj].style.visibility = "visible";
	if(document.getElementById) document.getElementById(obj).style.visibility = "visible";
}
function HideMenu(obj)
{
	if(document.layers) document.layers[obj].visibility = "hide";
	if(document.all && !document.getElementById) document.all[obj].style.visibility = "hidden";
	if(document.getElementById) document.getElementById(obj).style.visibility = "hidden";
}
function HideAll()
{
    HideMenu('menumuzeum');
    HideMenu('menuvystavy');
    HideMenu('menuprednasky');
    HideMenu('menusbirky');
    HideMenu('menupublikace');
    HideMenu('menuprogramy');
    HideMenu('menuprojekty');
}