关于javasript菜单的展开和隐藏?

你 2次指定onload,所以达不到想要的结果修改如下：
<html><head><title></title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<script language="JavaScript1.2">scores = new Array(50);var numTotal=0;NS4 = (document.layers) ? 1 : 0;IE4 = (document.all) ? 1 : 0;ver4 = (NS4 || IE4) ? 1 : 0;if (ver4) {    with (document) {        write("<STYLE TYPE='text/css'>");        if (NS4) {            write(".parent {position:absolute; visibility:visible}");            write(".child {position:absolute; visibility:visible}");            write(".regular {position:absolute; visibility:visible}")        }        else {            write(".child {display:none}")        }        write("</STYLE>");    }}function initIt(){    if (!ver4) return;    if (NS4) {        for (i=0; i<document.layers.length; i++) {            whichEl = document.layers[i];            if (whichEl.id.indexOf("Child") != -1) whichEl.visibility = "hide";       }        arrange();    }    else {        divColl = document.all.tags("DIV");        for (i=0; i<divColl.length; i++) {            whichEl = divColl(i);            if (whichEl.className == "child") whichEl.style.display = "none";        }    }}
function expandIt(el) { if (!ver4) return;    if (IE4) {        whichEl1 = eval(el + "Child"); for(i=1;i<=numTotal;i++){ whichEl = eval(scores[i] + "Child"); if(whichEl!=whichEl1) { whichEl.style.display = "none"; } }        whichEl1 = eval(el + "Child");        if (whichEl1.style.display == "none") {            whichEl1.style.display = "block";        }        else {            whichEl1.style.display = "none";        }    }    else {        whichEl = eval("document." + el + "Child"); for(i=1;i<=numTotal;i++){ whichEl = eval("document." + scores[i] + "Child"); if(whichEl!=whichEl1) { whichEl.visibility = "hide"; } }        if (whichEl.visibility == "hide") {            whichEl.visibility = "show";        }        else {            whichEl.visibility = "hide";        }        arrange();    }}</script>
</head><body onload="initIt();expandIt('KB1')">
<table border=0 ><tr><td align=left>
<div id='KB1Parent' class='parent'><A HREF="sss.asp?SearchClass=58" onClick="expandIt('KB1'); return false"><span class="text">大学</span></A><BR>
           </div><div id='KB1Child' class='child'>              <!---小类开始--->
              
<A HREF="default.asp?SearchClass2=61" ><span class="text">大一</span></A><BR>
<A HREF="default.asp?SearchClass2=62" ><span class="text">大二</span></A><BR>
<A HREF="default.asp?SearchClass2=63" ><span class="text">大三</span></A><BR>
<A HREF="default.asp?SearchClass2=67" ><span class="text">大四</span></A><BR>

 </div>  <!---小类结束----> <div id='KB2Parent' class='parent'><A HREF="sss.asp?SearchClass=59" onClick="expandIt('KB2'); return false"><span class="text">中学</span></A><BR>
           </div><div id='KB2Child' class='child'>              <!---小类开始--->
                    
              
<A HREF="default.asp?SearchClass2=64" ><span class="text">初一</span></A><BR>
              
<A HREF="default.asp?SearchClass2=65" ><span class="text">初二</span></A><BR>
              
<A HREF="default.asp?SearchClass2=66" ><span class="text">初三</span></A><BR>

 </div>  <!---小类结束----> <div id='KB3Parent' class='parent'><A HREF="sss.asp?SearchClass=60" onClick="expandIt('KB3'); return false"><span class="text">小学</span></A><BR>
           </div><div id='KB3Child' class='child'>              <!---小类开始---><A HREF="default.asp?SearchClass2=66" ><span class="text">一年级</span></A><BR>
      <A HREF="default.asp?SearchClass2=66" ><span class="text">二年级</span></A><BR>
                    
 </div>  <!---小类结束---->

<SCRIPT>numTotal=3;scores[1]='KB1';scores[2]='KB2';scores[3]='KB3';</SCRIPT>
 </td></tr></table>
</body></html>