导航处的a标签利用它的href属性，如<a href="#scroll"></a>
<p id="scroll"></p>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/htmlcharset=utf-8" />
<title>三级dropdown弹出菜单</title>
<style type="text/css">
/* common styling */
.menu {font-family: arial, sans-serifwidth:750pxposition:relativemargin:0font-size:11pxmargin:50px 0}
.menu ul li a, .menu ul li a:visited {display:blocktext-decoration:nonecolor:#000width:104pxheight:20pxtext-align:centercolor:#fffborder:1px solid #fffbackground:#710069line-height:20pxfont-size:11pxoverflow:hidden}
.menu ul {padding:0margin:0list-style-type: none}
.menu ul li {float:leftmargin-right:1pxposition:relative}
.menu ul li ul {display: none}
/* specific to non IE browsers */
.menu ul li:hover a {color:#fffbackground:#36f}
.menu ul li:hover ul {display:blockposition:absolutetop:21pxleft:0width:105px}
.menu ul li:hover ul li a.hide {background:#6a3color:#fff}
.menu ul li:hover ul li:hover a.hide {background:#6fccolor:#000}
.menu ul li:hover ul li ul {display: none}
.menu ul li:hover ul li a {display:blockbackground:#dddcolor:#000}
.menu ul li:hover ul li a:hover {background:#6fccolor:#000}
.menu ul li:hover ul li:hover ul {display:blockposition:absoluteleft:105pxtop:0}
.menu ul li:hover ul li:hover ul.left {left:-105px}
</style>
<!--[if lte IE 6]>
<style type="text/css">
.menu ul li a.hide, .menu ul li a:visited.hide {display:none}
.menu ul li a:hover ul li a.hide {display:none}
.menu ul li a:hover {color:#fffbackground:#36f}
.menu ul li a:hover ul {display:blockposition:absolutetop:21pxleft:0width:105px}
.menu ul li a:hover ul li a.sub {background:#6a3color:#fff}
.menu ul li a:hover ul li a {display:blockbackground:#dddcolor:#000}
.menu ul li a:hover ul li a ul {visibility:hidden}
.menu ul li a:hover ul li a:hover {background:#6fccolor:#000}
.menu ul li a:hover ul li a:hover ul {visibility:visibleposition:absoluteleft:105pxtop:0color:#000}
.menu ul li a:hover ul li a:hover ul.left {left:-105px}
</style>
<![endif]-->
</head>
<body>
<div class="menu">
<ul>
<li><a class="hide" href="../menu/index.html">DEMOS</a>
<!--[if lte IE 6]>
<a href="../menu/index.html">DEMOS
<table><tr><td>
<![endif]-->
<ul>
<li><a href="../menu/zero_dollars.html" title="The zero dollar ads page">zero dollars</a></li>
<li><a href="../menu/embed.html" title="Wrapping text around images">wrapping text</a></li>
<li><a href="../menu/form.html" title="Styling forms">styled form</a></li>
<li><a href="../menu/nodots.html" title="Removing active/focus borders">active focus</a></li>
<li><a class="hide" href="../menu/hover_click.html" title="Hover/click with no active/focus borders">HOVER/CLICK ></a>
<!--[if lte IE 6]>
<a class="sub" href="../menu/hover_click.html" title="Hover/click with no active/focus borders">HOVER/CLICK >
<table><tr><td>
<![endif]-->
<ul>
<li><a href="../menu/form.html" title="Styling forms">styled form</a></li>
<li><a href="../menu/nodots.html" title="Removing active/focus borders">active focus</a></li>
<li><a href="../menu/hover_click.html" title="Hover/click with no active/focus borders">hover/click</a></li>
</ul>
<!--[if lte IE 6]>
</td></tr></table>
</a>
<![endif]-->
</li>
<li><a href="../menu/shadow_boxing.html" title="Multi-position drop shadow">shadow boxing</a></li>
<li><a href="../menu/old_master.html" title="Image Map for detailed information">image map</a></li>
<li><a href="../menu/bodies.html" title="fun with background images">fun backgrounds</a></li>
<li><a href="../menu/fade_scroll.html" title="fade-out scrolling">fade scrolling</a></li>
<li><a href="../menu/em_images.html" title="em size images compared">em sized images</a></li>
</ul>
<!--[if lte IE 6]>
</td></tr></table>
</a>
<![endif]-->
</li>
<li><a class="hide" href="index.html">MENUS</a>
<!--[if lte IE 6]>
<a href="index.html">MENUS
<table><tr><td>
<![endif]-->
<ul>
<li><a href="spies.html" title="a coded list of spies">spies menu</a></li>
<li><a href="vertical.html" title="a horizontal vertical menu">vertical menu</a></li>
<li><a href="expand.html" title="an enlarging unordered list">enlarging list</a></li>
<li><a href="enlarge.html" title="an unordered list with link images">link images</a></li>
<li><a href="cross.html" title="non-rectangular links">non-rectangular</a></li>
<li><a href="jigsaw.html" title="jigsaw links">jigsaw links</a></li>
<li><a href="circles.html" title="circular links">circular links</a></li>
</ul>
<!--[if lte IE 6]>
</td></tr></table>
</a>
<![endif]-->
</li>
<li><a class="hide" href="../layouts/index.html">LAYOUTS</a>
<!--[if lte IE 6]>
<a href="../layouts/index.html">LAYOUTS
<table><tr><td>
<![endif]-->
<ul>
<li><a href="../layouts/bodyfix.html" title="Cross browser fixed layout">Fixed 1</a></li>
<li><a href="../layouts/body2.html" title="Cross browser fixed layout">Fixed 2</a></li>
<li><a href="../layouts/body4.html" title="Cross browser fixed layout">Fixed 3</a></li>
<li><a href="../layouts/body5.html" title="Cross browser fixed layout">Fixed 4</a></li>
<li><a href="../layouts/minimum.html" title="A simple minimum width layout">minimum width</a></li>
</ul>
<!--[if lte IE 6]>
</td></tr></table>
</a>
<![endif]-->
</li>
<li><a class="hide" href="../boxes/index.html">BOXES</a>
<!--[if lte IE 6]>
<a href="../boxes/index.html">BOXES
<table><tr><td>
<![endif]-->
<ul>
<li><a href="spies.html" title="a coded list of spies">spies menu</a></li>
<li><a href="vertical.html" title="a horizontal vertical menu">vertical menu</a></li>
<li><a href="expand.html" title="an enlarging unordered list">enlarging list</a></li>
<li><a href="enlarge.html" title="an unordered list with link images">link images</a></li>
<li><a href="cross.html" title="non-rectangular links">non-rectangular</a></li>
<li><a href="jigsaw.html" title="jigsaw links">jigsaw links</a></li>
<li><a href="circles.html" title="circular links">circular links</a></li>
</ul>
<!--[if lte IE 6]>
</td></tr></table>
</a>
<![endif]-->
</li>
<li><a class="hide" href="../mozilla/index.html">MOZILLA</a>
<!--[if lte IE 6]>
<a href="../mozilla/index.html">MOZILLA
<table><tr><td>
<![endif]-->
<ul>
<li><a href="../mozilla/dropdown.html" title="A drop down menu">drop down menu</a></li>
<li><a href="../mozilla/cascade.html" title="A cascading menu">cascading menu</a></li>
<li><a href="../mozilla/content.html" title="Using content:">content:</a></li>
<li><a href="../mozilla/moxbox.html" title=":hover applied to a div">mozzie box</a></li>
<li><a href="../mozilla/rainbow.html" title="I can build a rainbow">rainbow box</a></li>
<li><a href="../mozilla/snooker.html" title="Snooker cue">snooker cue</a></li>
<li><a href="../mozilla/target.html" title="Target Practise">target practise</a></li>
<li><a href="../mozilla/splittext.html" title="Two tone headings">two tone headings</a></li>
<li><a href="../mozilla/shadow_text.html" title="Shadow text">shadow text</a></li>
</ul>
<!--[if lte IE 6]>
</td></tr></table>
</a>
<![endif]-->
</li>
<li><a class="hide" href="../ie/index.html">EXPLORER</a>
<!--[if lte IE 6]>
<a href="../ie/index.html">EXPLORER
<table><tr><td>
<![endif]-->
<ul>
<li><a href="../ie/exampleone.html" title="Example one">example one</a></li>
<li><a href="../ie/weft.html" title="Weft fonts">weft fonts</a></li>
<li><a href="../ie/exampletwo.html" title="Vertical align">vertical align</a></li>
</ul>
<!--[if lte IE 6]>
</td></tr></table>
</a>
<![endif]-->
</li>
<li><a class="hide" href="../opacity/index.html">OPACITY</a>
<!--[if lte IE 6]>
<a href="../opacity/index.html">OPACITY
<table><tr><td>
<![endif]-->
<ul>
<li><a href="../opacity/colours.html" title="colour wheel">opaque colours</a></li>
<li><a href="../opacity/picturemenu.html" title="a menu using opacity">opaque menu</a></li>
<li><a href="../opacity/png.html" title="partial opacity">partial opacity</a></li>
<li><a href="../opacity/png2.html" title="partial opacity II">partial opacity II</a></li>
<li><a class="hide" href="../menu/hover_click.html" title="Hover/click with no active/focus borders"><HOVER/CLICK</a>
<!--[if lte IE 6]>
<a class="sub" href="../menu/hover_click.html" title="Hover/click with no active/focus borders"><HOVER/CLICK
<table><tr><td>
<![endif]-->
<ul class="left">
<li><a href="../menu/form.html" title="Styling forms">styled form</a></li>
<li><a href="../menu/nodots.html" title="Removing active/focus borders">active focus</a></li>
<li><a href="../menu/hover_click.html" title="Hover/click with no active/focus borders">hover/click</a></li>
</ul>
<!--[if lte IE 6]>
</td></tr></table>
</a>
<![endif]-->
</li>
</ul>
<!--[if lte IE 6]>
</td></tr></table>
</a>
<![endif]-->
</li>
</ul>
</div>
</body>
</html>
单纯用CSS也是做不出来的。需要搭配JS才可以。 起码CSS里面没有点击这个效果。
鼠标经过倒是可以。
<style type="text/css">
<!--
a {
text-decoration: none
}
span {
float:left
display:none
}
a:hover span{
display:inline
}
-->
</style>
</head>
<body>
<a href="#">这是标题<span>这是标题提示</span></a>
类似这样的效果。多设计个SPAN就可以。
不过CSS做出来的毕竟有局限性，IE6.0以下的版本对它的支持不是很好。
