var isDOM = (document.getElementById ? true : false); 
var isIE4 = ((document.all && !isDOM) ? true : false);
var isNS4 = (document.layers ? true : false);

// image directory
var imageDir = 'images/';

// menu variable
var menu = new Array();

function getRef(id) {
	if (isDOM) return document.getElementById(id);
	if (isIE4) return document.all[id];
	if (isNS4) return document.layers[id];
}

function getSty(id) {
	return (isNS4 ? getRef(id) : getRef(id).style);
} 

// Hide timeout.
var popTimer = 0;

// Array showing highlighted menu items.
var litNow = new Array();

function popOver(menuNum, itemNum) {

	clearTimeout(popTimer);

	hideAllBut(menuNum);

	litNow = getTree(menuNum, itemNum);

	changeCol(litNow, true);
	targetNum = menu[menuNum][itemNum].target;
	if (targetNum > 0) {
		thisX = parseInt(menu[menuNum][0].ref.left) + parseInt(menu[menuNum][itemNum].ref.left);
		thisY = parseInt(menu[menuNum][0].ref.top) + parseInt(menu[menuNum][itemNum].ref.top);
		with (menu[targetNum][0].ref) {
			left = parseInt(thisX + menu[targetNum][0].x);
			top = parseInt(thisY + menu[targetNum][0].y);
			visibility = 'visible';
      	}
   	}
}

function popOut(menuNum, itemNum) {
	
	if ((menuNum == 0) && !menu[menuNum][itemNum].target)
		hideAllBut(0)
	else
		popTimer = setTimeout('hideAllBut(0)', 500);
}

function getTree(menuNum, itemNum) {
	
	// Array index is the menu number. The contents are null (if that menu is not a parent)
	// or the item number in that menu that is an ancestor (to light it up).
	itemArray = new Array(menu.length);

	while(1) {
		itemArray[menuNum] = itemNum;
		// If we've reached the top of the hierarchy, return.
		if (menuNum == 0) return itemArray;
		itemNum = menu[menuNum][0].parentItem;
		menuNum = menu[menuNum][0].parentMenu;
   }
}

// Pass an array and a boolean to specify colour change, true = over colour.
function changeCol(changeArray, isOver) {
	var itemCount, currentImageID;
	for (menuCount = 0; menuCount < changeArray.length; menuCount++) {
		if (changeArray[menuCount]) {
			itemCount = changeArray[menuCount];
			newImg = isOver ? menu[menuCount][itemCount].moimg : menu[menuCount][itemCount].img;
			currentItemImageID = 'img' + 'menu' + menuCount + 'item' + itemCount;
	//		alert("currentIMAGEID: "+currentItemImageID +";IMAGESOURCE: "+imageDir+newImg);
			document.getElementById(currentItemImageID).src = imageDir + newImg;
			// Change the colours of the div/layer background.
/*			with (menu[menuCount][changeArray[menuCount]].ref) {
				if (isNS4) bgColor = newCol;
				else backgroundColor = newCol;
         	} */
      	}
   	}
}

function hideAllBut(menuNum) {
	
	var keepMenus = getTree(menuNum, 1);
	for (count = 0; count < menu.length; count++)
		if (!keepMenus[count])
			menu[count][0].ref.visibility = 'hidden';
	changeCol(litNow, false);
}

// *** MENU CONSTRUCTION FUNCTIONS ***

function Menu(isVert, popInd, x, y, width, overCol, backCol, borderClass, textClass) {
	// True or false - a vertical menu?
	this.isVert = isVert;
	// The popout indicator used (if any) for this menu.
	this.popInd = popInd
	// Position and size settings.
	this.x = x;
	this.y = y;
	this.width = width;
	// Colours of menu and items.
	this.overCol = overCol;
	this.backCol = backCol;
	// The stylesheet class used for item borders and the text within items.
	this.borderClass = borderClass;
	this.textClass = textClass;
	// Parent menu and item numbers, indexed later.
	this.parentMenu = null;
	this.parentItem = null;
	// Reference to the object's style properties (set later).
	this.ref = null;
}

function Item(img, moimg, href, frame, length, spacing, target) {
	this.img = img;
	this.moimg = moimg;
	this.href = href;
	this.frame = frame;
	this.length = length;
	this.spacing = spacing;
	this.target = target;
	// Reference to the object's style properties (set later).
	this.ref = null;
}

function writeMenus(menus) {
	menu = menus;
	
	if (!isDOM && !isIE4 && !isNS4) return;

	for (currMenu = 0; currMenu < menu.length; currMenu++) with (menu[currMenu][0]) {
		// Variable for holding HTML for items and positions of next item.
		var str = '', itemX = 0, itemY = 0;

		// Remember, items start from 1 in the array (0 is menu object itself, above).
		// Also use properties of each item nested in the other with() for construction.
		for (currItem = 1; currItem < menu[currMenu].length; currItem++) with (menu[currMenu][currItem]) {
			var itemID = 'menu' + currMenu + 'item' + currItem;

			// The width and height of the menu item - dependent on orientation!
			var w = (isVert ? width : length);
			var h = (isVert ? length : width);

			// Create a div or layer text string with appropriate styles/properties.
			// Thanks to Paul Maden (www.paulmaden.com) for helping debug this in IE4, apparently
			// the width must be a miniumum of 3 for it to work in that browser.
			if (isDOM || isIE4) {
				str += '<div id="' + itemID + '" style="position: absolute; left: ' + itemX + '; top: ' + itemY + '; width: ' + w + '; height: ' + h + '; visibility: inherit; ';
				if (backCol) str += 'background: ' + backCol + '; ';
				str += '" ';
			}
			if (isNS4) {
				str += '<layer id="' + itemID + '" left="' + itemX + '" top="' + itemY + '" width="' +  w + '" height="' + h + '" visibility="inherit" ';
				if (backCol) str += 'bgcolor="' + backCol + '" ';
			}
			//if (borderClass) str += 'class="' + borderClass + '" ';

			// Add mouseover handlers and finish div/layer.
			str += 'onMouseOver="popOver(' + currMenu + ',' + currItem + ')" onMouseOut="popOut(' + currMenu + ',' + currItem + ')">';

			// Add contents of item (default: table with link inside).
			// In IE/NS6+, add padding if there's a border to emulate NS4's layer padding.
			// If a target frame is specified, also add that to the <a> tag.

			//str += '<table width="' + (w - 8) + '" border="0" cellspacing="0" cellpadding="' + (!isNS4 && borderClass ? 3 : 0) + '"><tr>' + '<a ' + ' href="' + href + '"' + (frame ? ' target="' + frame + '">' : '>') + '<td class="' + textClass + '" align="left" height="' + (h - 7) + '">' + text + '</td></a>';
			//str += '<table width="' + (w - 8) + '" border="0" cellspacing="0" cellpadding="' + (!isNS4 && borderClass ? 3 : 0) + '"><tr><td align="left" height="' + (h - 7) + '">' + '<a class="' + textClass + '" href="' + href + '"' + (frame ? ' target="' + frame + '">' : '>') + text + '</a></td>';
			//str += '<table width="' + (w - 0) + '" border="0" cellspacing="0" cellpadding="' + (!isNS4 && borderClass ? 0 : 0) + '"><tr><td align="left" height="' + (h - 0) + '">' + '<a class="' + textClass + '" href="' + href + '"' + (frame ? ' target="' + frame + '">' : '>') ;
			str += '<IMG height=2 width="'+ width +'" src="' + imageDir + 'whiteline.gif" ><BR>';
			if (href != '') {
				str += '<a href="' + href + '"' + (frame ? ' target="' + frame + '">' : '>') ;
				str += '<img border="0" id=img' + itemID + ' src="' + imageDir + img +'" >' + '</a>';
			} else {
				str += '<img border="0" id=img' + itemID + ' src="' + imageDir + img +'" >';
			}
			
			if (currItem == menu[currMenu].length-1)
				str += '<IMG width="'+ width +'" src="' + imageDir + 'whiteline.gif" >';
				
			if (target > 0) {
				// Set target's parents to this menu item.
				menu[target][0].parentMenu = currMenu;
				menu[target][0].parentItem = currItem;

				// Add a popout indicator.
				//if (popInd) str += '<td class="' + textClass + '" align="right">' + popInd + '</td>';
			}
			//str += '</tr></table>' + (isNS4 ? '</layer>' : '</div>');
			str +=  (isNS4 ? '</layer>' : '</div>');
			if (isVert) itemY += length + spacing;
			else itemX += length + spacing;
		}

		
		if (isDOM) {
			var newDiv = document.createElement('div');
			document.getElementsByTagName('body').item(0).appendChild(newDiv);
			newDiv.innerHTML = str;
			ref = newDiv.style;
			ref.position = 'absolute';
			ref.visibility = 'hidden';
		}

		// Insert a div tag to the end of the BODY with menu HTML in place for IE4.
		if (isIE4) {
			document.body.insertAdjacentHTML('beforeEnd', '<div id="menu' + currMenu + 'div" ' + 'style="position: absolute; visibility: hidden">' + str + '</div>');
			ref = getSty('menu' + currMenu + 'div');
		}

		// In NS4, create a reference to a new layer and write the items to it.
		if (isNS4) {
			ref = new Layer(0);
			ref.document.write(str);
			ref.document.close();
		}

		for (currItem = 1; currItem < menu[currMenu].length; currItem++) {
			itemName = 'menu' + currMenu + 'item' + currItem;
			if (isDOM || isIE4) menu[currMenu][currItem].ref = getSty(itemName);
			if (isNS4) menu[currMenu][currItem].ref = ref.document[itemName];
   		}
	}
	
	with(menu[0][0]) {
		ref.left = x;
		ref.top = y;
		ref.visibility = 'visible';
   }
}

// Syntaxes: *** START EDITING HERE, READ THIS SECTION CAREFULLY! ***
//
// menu[menuNumber][0] = new Menu(Vertical menu? (true/false), 'popout indicator', left, top,
// width, 'mouseover colour', 'background colour', 'border stylesheet', 'text stylesheet');
//
// Left and Top are measured on-the-fly relative to the top-left corner of its trigger, or
// for the root menu, the top-left corner of the page.
//
// menu[menuNumber][itemNumber] = new Item('Text', 'URL', 'target frame', length of menu item,
//  additional spacing to next menu item, number of target menu to popout);
//
// If no target menu (popout) is desired, set it to 0. Likewise, if your site does not use
// frames, pass an empty string as a frame target.
//
// Something that needs explaining - the Vertical Menu setup. You can see most menus below
// are 'true', that is they are vertical, except for the first root menu. The 'length' and
// 'width' of an item depends on its orientation -- length is how long the item runs for in
// the direction of the menu, and width is the lateral dimension of the menu. Just look at
// the examples and tweak the numbers, they'll make sense eventually :).


// *** OPTIONAL CODE FROM HERE DOWN ***

// These two lines handle the window resize bug in NS4. See <body onResize="...">.
// I recommend you leave this here as otherwise when you resize NS4's width menus are hidden.

var popOldWidth = window.innerWidth;
nsResizeHandler = new Function('if (popOldWidth != window.innerWidth) location.reload()');


// This is a quick snippet that captures all clicks on the document and hides the menus
// every time you click. Use if you want.

if (isNS4) document.captureEvents(Event.CLICK);
document.onclick = clickHandle;

function clickHandle(evt)
{
 if (isNS4) document.routeEvent(evt);
 hideAllBut(0);
}


// This is just the moving command for the example.

function moveRoot()
{
 with(menu[0][0].ref) left = ((parseInt(left) < 100) ? 100 : 5);
}