Js点击弹出下拉菜单效果实例

<STYLE type=text/css> 
.menu { BORDER-RIGHT: #006080 2px solid; BORDER-TOP: #80e0ff 2px solid; LEFT: 0px; VISIBILITY: hidden; BORDER-LEFT: #80e0ff 2px solid; BORDER-BOTTOM: #006080 2px solid; POSITION: absolute; TOP: 0px; BACKGROUND-COLOR: #40a0c0 } 
A.menuItem { BORDER-RIGHT: #000000 0px solid; PADDING-RIGHT: 12px; BORDER-TOP: #000000 0px solid; DISPLAY: block; PADDING-LEFT: 8px; FONT-WEIGHT: bold; FONT-SIZE: 8pt; PADDING-BOTTOM: 2px; BORDER-LEFT: #000000 0px solid; CURSOR: default; COLOR: #ffffff; PADDING-TOP: 2px; BORDER-BOTTOM: #000000 0px solid; FONT-FAMILY: MS Sans Serif, Arial, Tahoma, sans-serif; TEXT-DECORATION: none } 
A.menuItem:hover { COLOR: #ffff00; BACKGROUND-COLOR: #004060 } 
</STYLE> 
<DIV class=menu id=myMenu><A class=menuItem 
href="https://3water.com">三水点靠木</A> <A class=menuItem 
href="http://www.baidu.com">百度</A> <A class=menuItem 
href="">网 易</A> <A class=menuItem 
href="">江苏音符</A> <A class=menuItem 
href="">央视国际</A> </DIV> 
<P><font onclick="openMenu(event, 'myMenu');return false;">点击打开菜单</font></P> 
<SCRIPT type=text/javascript> 
document.getElementById("myMenu").onmouseout = closeMenu; 
function openMenu(event, id) { 
var el, x, y; 
el = document.getElementById(id); 
if (window.event) { 
x = window.event.clientX + document.documentElement.scrollLeft 
+ document.body.scrollLeft; 
y = window.event.clientY + document.documentElement.scrollTop + 
+ document.body.scrollTop; 
} 
else { 
x = event.clientX + window.scrollX; 
y = event.clientY + window.scrollY; 
} 
x -= 2; y -= 2; 
el.style.left = x + "px"; 
el.style.top = y + "px"; 
el.style.visibility = "visible"; 
} 
function closeMenu(event) { 
var current, related; 
if (window.event) { 
current = this; 
related = window.event.toElement; 
} 
else { 
current = event.currentTarget; 
related = event.relatedTarget; 
} 
if (current != related && !contains(current, related)) 
current.style.visibility = "hidden"; 
} 
function contains(a, b) { 
// Return true if node a contains node b. 
while (b.parentNode) 
if ((b = b.parentNode) == a) 
return true; 
return false; 
} 
</SCRIPT> </td>
   </tr>
 </table>