有下面的代码，现在想实现的目标是：
1.页面打开后菜单默认是收敛的，点击某个才弹出子菜单。
2.点击某个具体的页面时，菜单框架显示不变，只在右边显示页面信息。
请问如何实现？高手帮忙！
或者哪位有实例代码共享下！
<script language="JavaScript">
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 getIndex(el) {
    ind = null;
    for (i=0; i<document.layers.length; i++) {
        whichEl = document.layers[i];
        if (whichEl.id == el) {
            ind = i;
            break;
        }
    }
    return ind;
}
function arrange() {
    nextY = document.layers[firstInd].pageY +document.layers[firstInd].document.height;
    for (i=firstInd+1; i<document.layers.length; i++) {
        whichEl = document.layers[i];
        if (whichEl.visibility != "hide") {
            whichEl.pageY = nextY;
            nextY += whichEl.document.height;
        }
    }
}
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) {
        whichEl = eval(el + "Child");
        if (whichEl.style.display == "none") {
            whichEl.style.display = "block";
        }
        else {
            whichEl.style.display = "none";
        }
    }
    else {
        whichEl = eval("document." + el + "Child");
        if (whichEl.visibility == "hide") {
            whichEl.visibility = "show";
        }
        else {
            whichEl.visibility = "hide";
        }
        arrange();
    }
}
onload = initIt;
</script>
        </font></p>
      <div id="KB1Parent" class="parent">　　　　<a href="#" onClick="expandIt('KB1'); return false" ><img src="img/plus.gif" border=0>文件夹一</a></div>
      <div id="KB1Child" class="child">　　　　　<a href="sample.htm" target="_blank" ><img src="img/spacer.gif"  border=0 alt=""><img src="img/open.gif"  border=0>页面一</a><br>
        　　　　　<a href="sample.htm" target="_blank" ><img src="img/spacer.gif"  border=0 alt="" width="15" height="11"><img src="img/open.gif"  border=0>页面二</a><br>
        　　　　　<a href="sample.htm" target="_blank" ><img src="img/spacer.gif"  border=0 alt="" width="15" height="11"><img src="img/open.gif"  border=0>页面三</a></div>
      <div id="KB2Parent" class="parent">　　　　<a href="#" onClick="expandIt('KB2'); return false" ><img src="img/plus.gif" border=0>文件夹二</a></div>
      <div id="KB2Child" class="child">　　　　　<a href="sample.htm" target="_blank" ><img src="img/spacer.gif"  border=0 alt="" width="15" height="11"><img src="img/open.gif"  border=0>页面一</a><br>
        　　　　　<a href="sample.htm" target="_blank" ><img src="img/spacer.gif"  border=0 alt=""><img src="img/open.gif"  border=0>页面二</a><br>
        　　　　　<a href="sample.htm" target="_blank" ><img src="img/spacer.gif"  border=0 alt="" width="15" height="11"><img src="img/open.gif"  border=0>页面三</a></div>
      <div id="KB3Parent" class="parent">　　　　<a href="#" onClick="expandIt('KB3'); return false" ><img src="img/plus.gif"  border=0>文件夹三</a></div>
      <div id="KB3Child" class="child"> 　　　　　<a href="sample.htm" target="_blank" ><img src="img/spacer.gif"  border=0 alt=""><img src="img/open.gif"  border=0>页面一</a><br>
        　　　　　　<a href="sample.htm" target="_blank" ><img src="img/open.gif"  border=0>页面二</a><br>
        　　　　　<a href="sample.htm" target="_blank" ><img src="img/spacer.gif"  border=0 alt=""><img src="img/open.gif"  border=0>页面三</a></div>
      <script language="JavaScript">
if (NS4) {
        firstEl = "KB1Parent";
        firstInd = getIndex(firstEl);
        arrange();
}
</script>