// Page 352 Sams teach yourself javascript in 24 hours
// global variables for timeout and for currrent menu

var t=false,current;
function SetupMenu() {
if (!document.getElementsByTagName) return;
items=document.getElementsByTagName("li");
for (i=0; i<items.length; i++) {
if (items[i].className != "menu") continue;


// if (items[i].className != "sitemap") continue;



// set up event handlers
thelink=findChild(items[i],"A");
thelink.onmouseover=ShowMenu;
thelink.onmouseout=StartTimer;

// this is a submenu?
if (ul=findChild(items[i],"UL")) {
ul.style.display="none";
for (j=0; j<ul.childNodes.length; j++) {
ul.childNodes[j].onmouseover=ResetTimer;
ul.childNodes[j].onmouseout=StartTimer;
}
}
}




for (i=0; i<items.length; i++) {
// if (items[i].className != "menu") continue;


if (items[i].className != "sitemap") continue;



// set up event handlers
thelink=findChild(items[i],"A");
thelink.onmouseover=ShowMenu;
thelink.onmouseout=StartTimer;

// this is a submenu?
if (ul=findChild(items[i],"UL")) {
ul.style.display="none";
for (j=0; j<ul.childNodes.length; j++) {
ul.childNodes[j].onmouseover=ResetTimer;
ul.childNodes[j].onmouseout=StartTimer;
}
}
}














}

//find the first child object of a particular type

function findChild(obj,tag) {
cn = obj.childNodes;
for (k=0; k<cn.length; k++) {
if (cn[k].nodeName==tag) return cn[k];
}
return false;
}

function ShowMenu(e) {
if (!e) var e = window.event;

// which link was the mouse over?
thislink = (e.target) ? e.target: e.srcElement;
ResetTimer();

//hide the previous menu, if any
if (current) HideMenu(current);

// we want the LI, not the link
thislink = thislink.parentNode;
current=thislink;

// find the submenu, if any
ul = findChild(thislink,"UL");
if (!ul) return;
ul.style.display="block";
}

function HideMenu(thelink) {

// find the submenu, if any
ul = findChild(thelink, "UL");
if (!ul) return;
ul.style.display="none";
}

function ResetTimer() {
if (t) window.clearTimeout(t);
}

function StartTimer() {
t = window.setTimeout("HideMenu(current)",200);
}

// set up the menu when the page loads
window.onload=SetupMenu;