var isDOM = (document.getElementById ? true : false); 

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

var isNS4 = (document.layers ? true : false);



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) {

	for (menuCount = 0; menuCount < changeArray.length; menuCount++) {

		if (changeArray[menuCount]) {

			newCol = isOver ? menu[menuCount][0].overCol : menu[menuCount][0].backCol;

// 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(text, href, frame, length, spacing, target) {

	this.text = text;

	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() {

	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><td align="left" height="' + (h - 7) + '">' + '<a class="' + textClass + '" href="' + href + '"' + (frame ? ' target="' + frame + '">' : '>') + text + '</a></td>';

		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>');

		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.position = 'relative';

		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 :).



	var menu = new Array();



// Default colours passed to most menu constructors (just passed to functions, not

// a global variable - makes things easier to change later in bulk).

//	var defOver = '#80AFFC', defBack = '#629DFD';

	var defOver = '#BEDFFC', defBack = '#FFFFFF';



// Default 'length' of menu items - item height if menu is vertical, width if horizontal.

	var defLength = 22;





// Menu 0 is the special, 'root' menu from which everything else arises.

	menu[0] = new Array();

// A non-vertical menu with a few different colours and no popout indicator, as an example.

// *** MOVE ROOT MENU AROUND HERE ***  it's positioned at (5, 0) and is 17px high now.

	menu[0][0] = new Menu(false, '', 10, 2, 17, '#80AFFC', '#629DFD', '', 'headText');

// Notice how the targets are all set to nonzero values...

// The 'length' of each of these items is 40, and there is spacing of 10 to the next item.

// Most of the links are set to '#' hashes, make sure you change them to actual files.

//	menu[0][1] = new Item('[ Home ]', '#', '', 40, 10, 0);

	menu[0][1] = new Item('[ 首頁 ]', 'index.html', '', 45, 1, 0);

	menu[0][2] = new Item('[ 簡介 ]', '#', '', 45, 1, 2);

	menu[0][3] = new Item('[ 學系 ]', '#', '', 45, 1, 3);

// An example of a link with a target frame/window as well...

//	menu[0][4] = new Item('[ 發展策略 ]', '#', '', 70, 1, 4);

	menu[0][4] = new Item('[ 網站一覽 ]', 'sitemap.html', '', 70, 1, 0);

	menu[0][5] = new Item('[ 聯絡 ]', 'contact.html', '', 45, 1, 0);

	menu[0][6] = new Item('<img src="../images/text_en.jpg" border="0">', '../en/index.html', '', 50, 1, 0);



// File menu.

	menu[1] = new Array();

// The File menu is positioned 0px across and 22 down from its trigger, and is 80 wide.

// All text in this menu has the stylesheet class 'item' -- see the <style> section above.

// We've passed a 'greater-than' sign '>' as a popout indicator. Try an image...?

	menu[1][0] = new Menu(true, '#', 0, 22, 80, defOver, defBack, 'itemBorder', 'itemText');

//	menu[1][1] = new Item('Open', '#', '', defLength, 0, 0);

//	menu[1][2] = new Item('Save', '#', '', defLength, 0, 0);

// Non-zero target means this will trigger a popout -- menu[4] which is the 'Reopen' menu.

//	menu[1][3] = new Item('Reopen', '#', '', defLength, 0, 4);

//	menu[1][4] = new Item('Exit', '#', '', defLength, 0, 0);



// Edit menu.

	menu[2] = new Array();
	
	menu[2][0] = new Menu(true, '>', 0, 22, 110, defOver, defBack, 'itemBorder', 'itemText');
	
	menu[2][1] = new Item('院長的話', 'message.html', '', defLength, 0, 0);
	menu[2][2] = new Item('文學院之使命', 'mission.html', '', defLength, 0, 0);
	
	//menu[2][3] = new Item('院長演辭', 'dean_speech.html', '', defLength, 0, 0);

// Help menu

	menu[3] = new Array();

	menu[3][0] = new Menu(true, '>', 0, 22, 150, defOver, defBack, 'itemBorder', 'itemText');

	menu[3][1] = new Item('人類學系', 'dept_ant.html', '', defLength, 0, 0);

	menu[3][2] = new Item('中國語言及文學系', 'dept_ch.html', '', defLength, 0, 0);
	
	menu[3][3] = new Item('文化及宗教研究系', 'dept_crs.html', '', defLength, 0, 0);

	menu[3][4] = new Item('英文系', 'dept_en.html', '', defLength, 0, 0);

	menu[3][5] = new Item('藝術系', 'dept_fa.html', '', defLength, 0, 0);

	menu[3][6] = new Item('歷史系', 'dept_hi.html', '', defLength, 0, 0);

	menu[3][7] = new Item('日本研究學系', 'dept_ja.html', '', defLength, 0, 0);

	menu[3][8] = new Item('語言學及現代語言系', 'dept_lin.html', '', defLength, 0, 0);

	menu[3][9] = new Item('音樂系', 'dept_mu.html', '', defLength, 0, 0);

	menu[3][10] = new Item('哲學系', 'dept_ph.html', '', defLength, 0, 0);

	menu[3][11] = new Item('翻譯系', 'dept_tr.html', '', defLength, 0, 0);
	
	menu[3][12] = new Item('英語教學單位', 'dept_elt.html', '', defLength, 0, 0);

	menu[3][13] = new Item('雅禮中國語文研習所', 'dept_clc.html', '', defLength, 0, 0);


// Reopen menu

	menu[4] = new Array();

// This is across but not down... a horizontal popout (with crazy stylesheets :)...

//	menu[4][0] = new Menu(true, '>', 0, 22, 240, '#80AFFC', '#629DFD', 'itemBorder', 'itemText');

	menu[4][0] = new Menu(true, '>', 0, 22, 150, defOver, defBack, 'itemBorder', 'itemText');

// These items are lengthier than normal, and have extra spacing due to the fancy borders.

/*	menu[4][1] = new Item('人類學系', 'http://www.cuhk.edu.hk/ant/', '', defLength, 0, 0);
	
	menu[4][2] = new Item('中國語文及文學系', 'plan_ch.html', '', defLength, 0, 0);

	menu[4][3] = new Item('文化及宗教研究系', 'plan_re.html', '', defLength, 0, 0);

	menu[4][4] = new Item('英文系', 'plan_en.html', '', defLength, 0, 0);

	menu[4][5] = new Item('藝術系', 'plan_fa.html', '', defLength, 0, 0);

	menu[4][6] = new Item('歷史系', 'plan_hi.html', '', defLength, 0, 0);

	menu[4][7] = new Item('日本研究學系', 'plan_ja.html', '', defLength, 0, 0);

	menu[4][8] = new Item('語言學及現代語言系', 'dept_ml.html', '', defLength, 0, 0);

	menu[4][9] = new Item('音樂系', 'plan_mu.html', '', defLength, 0, 0);

	menu[4][10] = new Item('哲學系', 'plan_ph.html', '', defLength, 0, 0);

	menu[4][11] = new Item('翻譯系', 'plan_tr.html', '', defLength, 0, 0);

	menu[4][12] = new Item('英語教學單位', 'plan_elt.html', '', defLength, 0, 0);

	menu[4][13] = new Item('語文自學中心', 'http://www.ilc.cuhk.edu.hk/', '', defLength, 0, 0);
*/

// Reopen menu

	menu[5] = new Array();

// This is across but not down... a horizontal popout (with crazy stylesheets :)...

	menu[5][0] = new Menu(true, '>', 0, 22, 120, '#80AFFC', '#629DFD', 'itemBorder', 'itemText'); 

// These items are lengthier than normal, and have extra spacing due to the fancy borders.

//	menu[5][1] = new Item('WebCT', 'http://course.cuhk.edu.hk/', '', defLength, 0, 0);

//	menu[5][2] = new Item('CUHK', 'http://www.cuhk.edu.hk/', '', defLength, 0, 0);



// Help About popout

//	Menu[6] = new Array();

// Leftwards popout with a negative x and y relative to its trigger.

//	menu[6][0] = new Menu(true, '>', -85, -17, 80, defOver, defBack, 'itemBorder', 'itemText');

//	menu[6][1] = new Item('Web Class', '#', '', 40, 0, 0);



//	Menu[7] = new Array();

// Leftwards popout with a negative x and y relative to its trigger.

//	menu[7][0] = new Menu(true, '>', -85, -17, 80, defOver, defBack, 'itemBorder', 'itemText');









// *** 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);

}



function sayHello(){

	alert("Hello!");	

}