<div id="wrap">
<ul id="menu">
<li><a href="">撤銷(xiāo)</a></li>
<li><a href="">重做</a></li>
<li><a href="">復(fù)制</a></li>
<li><a href="">粘貼</a></li>
<li><a href="">大小寫(xiě)轉(zhuǎn)換</a></li>
<li><a href="">回車(chē)</a></li>
<li><a href="">拼寫(xiě)檢查</a></li>
<li><a href="">新建</a></li>
<li><a href="">自定義</a></li>
<li><a href="">圖形選項(xiàng)</a></li>
<li class="no"><a href="">關(guān)閉</a></li>
</ul>
</div>

function $(id) {
return document.getElementById(id);
};

var EventUnit = {
addHandler: function(element, type, handler) {//添加事件處理程序
if(element.addEventListener) {
element.addEventListener(type, handler, false);
} else if(element.attachEvent) {
element.attachEvent('on' + type, handler);
} else {
element['on' + type] = handler;
};
},
getEvent: function(event) {
return event ? event : window.event;
},
preventDefault: function(event) {//取消事件默認(rèn)動(dòng)作
if(event.preventDefault) {
event.preventDefault();
} else {
event.returnValue = false;
};
}
}

EventUnit.addHandler(window, 'load', function() {
var wrap = $('wrap');
var menu = $('menu');
var menuStyle = menu.style.display;
var x = wrap.offsetLeft + wrap.clientWidth, y = wrap.offsetTop + wrap.clientHeight;
var w = 0, h = 0;
var left = 0, top = 0;

EventUnit.addHandler(wrap, 'contextmenu', function(event) {
event = EventUnit.getEvent(event);
EventUnit.preventDefault(event);

menu.style.display = 'block';
w = menu.clientWidth;
h = menu.clientHeight;
left = (x - event.clientX >= w) ? event.clientX - wrap.offsetLeft : event.clientX - wrap.offsetLeft - w;
top = (event.clientY + h <= y) ? event.clientY - wrap.offsetTop : event.clientY - wrap.offsetTop - h;
menu.style.left = left + 'px';
menu.style.top = top + 'px';
});

EventUnit.addHandler(document, 'click', function() {
menu.style.display = menuStyle;
});
});