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演示效果：请看上面的菜单

代码提示：按说明和注释复制代码

一：将下面的代码放在<HEAD>与</HEAD>之间
<SCRIPT LANGUAGE="JavaScript">

<!-- Begin
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.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 = '#336699', defBack = '#003366';

// 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, '', 5, 0, 17, '#669999', '#1EAE49', '', 'itemText');
// 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('  文件', 'http://www.51javascript.net', '', 40, 10, 1);
menu[0][2] = new Item('  编缉', 'http://www.51javascript.net', '', 40, 10, 2);
menu[0][3] = new Item('  帮助', 'http://www.51javascript.net', '', 40, 10, 3);
// An example of a link with a target frame/window as well...
menu[0][4] = new Item('  站点', 'http://www.51javascript.net', '_new', 40, 10, 0);

// File menu.
menu[1] = new Array();
// 修改下面的文字及对应的链接地址
// 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('打开', 'http://www.51javascript.net', '', defLength, 0, 0);
menu[1][2] = new Item('保存', 'http://www.51javascript.net', '', defLength, 0, 0);
// Non-zero target means this will trigger a popout -- menu[4] which is the 'Reopen' menu.
menu[1][3] = new Item('打开为', 'http://www.51javascript.net', '', defLength, 0, 4);
menu[1][4] = new Item('退出', 'http://www.51javascript.net', '', defLength, 0, 0);

// Edit menu.
menu[2] = new Array();
menu[2][0] = new Menu(true, '>', 0, 22, 80, defOver, defBack, 'itemBorder', 'itemText');
menu[2][1] = new Item('剪切', 'http://www.51javascript.net', '', defLength, 0, 0);
menu[2][2] = new Item('复制', 'http://www.51javascript.net', '', defLength, 0, 0);
menu[2][3] = new Item('粘贴', 'http://www.51javascript.net', '', defLength, 0, 0);

// Help menu
menu[3] = new Array();
menu[3][0] = new Menu(true, '<', 0, 22, 80, defOver, defBack, 'itemBorder', 'itemText');
menu[3][1] = new Item('内容', 'http://www.51javascript.net', '', defLength, 0, 0);
menu[3][2] = new Item('索引', 'http://www.51javascript.net', '', defLength, 0, 0);
menu[3][3] = new Item('关于本站', 'http://www.51javascript.net', '', defLength, 0, 5);

// Reopen menu
menu[4] = new Array();
// This is across but not down... a horizontal popout (with crazy stylesheets :)...
menu[4][0] = new Menu(true, '>', 85, 0, 120, '#333366', '#666699', 'crazyBorder', 'crazyText');
// These items are lengthier than normal, and have extra spacing due to the fancy borders.
menu[4][1] = new Item('Recent Doc 1:<br>Schedule', '#', '', 36, 4, 0);
menu[4][2] = new Item('Recent Doc 2:<br>Plan', '#', '', 36, 7, 0);
menu[4][3] = new Item('Etc. etc...', '#', '', defLength, 0, 0);

// Help About popout
menu[5] = new Array();
// Leftwards popout with a negative x and y relative to its trigger.
menu[5][0] = new Menu(true, '>', -85, -17, 80, defOver, defBack, 'itemBorder', 'itemText');
menu[5][1] = new Item('Leftwards!<br>And up!', '#', '', 40, 0, 0);

// *** 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);
}
// End -->
</script>

<style>
<!--

.itemBorder { border: 1px solid black }
.itemText { text-decoration: none; color: #FFFFFF; font: 12px Arial, Helvetica }

.crazyBorder { border: 2px outset #663399 }
.crazyText { text-decoration: none; color: #FFCC99; font: Bold 12px Arial, Helvetica }

-->
</style>

二：修改<body***>中的内容，将下面的代码加入原<body***>中
<BODY marginwidth="0" marginheight="0" style="margin: 0" BGCOLOR=#ffffff vlink=#0000ff onLoad="writeMenus()" onResize="if (isNS4) nsResizeHandler()">

三：将下面的代码复制到〈BODY〉区

<table bgcolor="#1EAE49" width="100%" border="0" cellpadding="0" cellspacing="0">
<tr><td height="17"><font size="1"> </font></td></tr></table>
<BR>
<center>
<table BORDER=0 WIDTH=486 CELLPADDING=3 CELLSPACING=0>
<tr>
<td><font FACE="helvetica,arial,geneva"> </font></td>
</tr>
</table>

</center>
</center>

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