下拉菜单的导航条 - 菜单/导航条代码

function MM_findObj(n, d) { //v4.0
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0 && parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n]) && d.all) x=d.all[n]; for (i=0;!x && i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x && d.layers && i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x  &&  document.getElementById) x=document.getElementById(n); return x;
}
//-->
</SCRIPT>
<SCRIPT language=JavaScript>
<!--

menuPrefix = 'menu';  // Prefix that all menu layers must start with
                      // All layers with this prefix will be treated
                      // as a part of the menu system.

var menuTree, mouseMenu, hideTimer, doHide;

function init() {
  ie4 = (document.all)?true:false;
  ns4 = (document.layers)?true:false;
  document.onmousemove = mouseMove;
  if (ns4) { document.captureEvents(Event.MOUSEMOVE); }
}

function showObject(obj) {
  if (ie4) { document.all[obj].style.visibility = "visible"; }
  else if (ns4) { document.layers[obj].visibility = "show";  }
}

function hideObject(obj) {
  if (ie4) { document.all[obj].style.visibility = "hidden"; }
  else if (ns4) { document.layers[obj].visibility = "hide"; }
}

function hideMe(hide) {
    if (hide) {
        if (doHide) { hideAll(); }
    }
    else {
        doHide = true;
        hideTimer = window.setTimeout("hideMe(true);", 2000);
    }
}

function mouseMove(e) {
  if (ie4) { mouseY = window.event.y; }
  if (ns4) { mouseY = e.pageY; }
}

function itemHover(obj,src,text,style) {
  if (ns4) {
    var text = '<nobr><a href="' + src + '" class="' + style + '">' + text + '<\/a><\/nobr>'
    obj.document.open();
    obj.document.write(text);
    obj.document.close();
  }
}

onload = init;
//-->
</SCRIPT>
<style type=text/css>
<!--
  .menu                   { position: absolute; left: 0; top: 2;
                             visibility: hidden; background: #FFFFFF;
                             width: 100px; margin: 0px 0px; padding: 0px 0px;
                             border: 1px silver solid;
                             overflow: visible; ; clip:     rect(   )}
.menu a:visited { font-family: "Tahoma"; font-size: 11px;
                             text-decoration: none; font-weight: normal;
                             color: black; background: #E2E2E2;
                             width: 108px; padding-left: 8px; ; line-height: 22px; border-color: #FFFFFF #666666 #333333 #999999; border-style: solid; border-top-width: 1px; border-right-width: 1px; border-bottom-width: 1px; border-left-width: 1px; clip:  rect(   )}
  .menu a:hover            { font-family: "Tahoma"; font-size: 11px;
                             text-decoration: none; font-weight: normal;
                             color: #FFFFFF; background: #009900;
                             width: 108px; padding-left: 8px; ; line-height: 22px; clip:  rect(   )}
  .menu .border            { border: 1px solid #F4F4F4;
                             border-bottom: 1px solid #808080;
                             border-right: 1px solid #808080; }
  .menu .text              { overflow: hidden;
                             width: 125px; height: 15px; }
  .menu .arrow             { overflow: hidden;
                             width: 15px; height: 12px;
                             padding-left: 5px; padding-top: 3px; }
  .menu .arrow img         { width: 6px; height: 7px;
                             border: 0px; }  .menu a { font-family: "Tahoma"; font-size: 11px;
                             text-decoration: none; font-weight: normal;
                             color: black; background: #E2E2E2;
                             width: 108px; padding-left: 8px;  ; clip:  rect(   ); border-color: #FFFFFF #666666 #333333 #999999; border-style: solid; border-top-width: 1px; border-right-width: 1px; border-bottom-width: 1px; border-left-width: 1px; line-height: 22px} .menu a:link {  color: #000000; text-decoration: none}

.a {  font-size: 12px; text-decoration: none}
a:link {  color: #FFFFFF; text-decoration: none}
a:hover {  text-decoration: underline}
a:visited {  color: #FFFFFF; text-decoration: none}
-->
</style>
</head>

<body bgcolor="#FFFFFF" text="#000000" leftmargin="0" topmargin="0">
<table border="0" cellpadding="0" cellspacing="1" bgcolor="#333333" width="778" class="a">
  <tr bgcolor="#009830" align="center" valign="bottom"> 
    <td width="10" height="18"> </td>
    <td width="74"><a href="#;"  onMouseOver="expandMenu(null,'menu1',getPos(this,'Left'),getPos(this,'Top')+this.offsetHeight);" class="a" >第一项</a></td>
    <td width="58"><a href="#;"  onMouseOver="expandMenu(null,'menu2',getPos(this,'Left'),getPos(this,'Top')+this.offsetHeight);" class="a" >第二项</a></td>
    <td width="58"><a href="#;"  onMouseOver="expandMenu(null,'menu3',getPos(this,'Left'),getPos(this,'Top')+this.offsetHeight);" class="a" >第三项</a></td>
    
    <td width="40"><a href="#;" class="a" >首页</a></td>
    <td width="18" height="18"> </td>
  </tr>
</table>
<script language="JavaScript">
function getPos(el,sProp) { 
    var iPos = 0
    while (el!=null) {
        iPos+=el["offset" + sProp]
        el = el.offsetParent
    }
    return iPos

}
</script>

<div id="menu1" class="menu" onMouseOut="hideMe();" style="">
  <a href="#;" onMouseOver="expandMenu('menu1');">第一项</a>

</div>

<div id="menu2" class="menu" onMouseOut="hideMe();"> 
  <a href="#;" onMouseOver="expandMenu('menu2');">第二项</a>

</div>

<div id="menu3" class="menu" onMouseOut="hideMe();"> 
  <a href="#;" onMouseOver="expandMenu('menu3');">第三项</a>

</div>

<p class="a"> </p>
</body>
</html>