简单的js树状目录

<script language="JavaScript">
with (document) {
        write("<STYLE TYPE='text/css'>");
        write(".child {display:none}")
        write("</STYLE>");
    }
function initIt(){
        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) {

        whichEl = eval(el + "Child");
        if (whichEl.style.display == "none") {
            whichEl.style.display = "block";
        }
        else {
            whichEl.style.display = "none";
        }
    }
onload = initIt;
</script>
<LINK href=main.css rel=stylesheet type=text/css>
        </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="#" onClick="expandIt('KB1_1'); return false" ><img src="img/spacer.gif"  border=0 alt=""><img src="img/plus.gif"  border=0>目录2</a><br>
      <div id="KB1_1Child" class="child">
      <a href="#" onClick="expandIt('KB1_1_1'); return false"><img src="img/spacer.gif" border=0 alt="" width="15" height="11"><img src="img/spacer.gif" border=0 alt="" width="15" height="11"><img src="img/plus.gif" border=0>内部1<br>
      <div id="KB1_1_1Child" class="child">
      <a href="sample.htm" target=_blank><img src="img/spacer.gif" border=0 alt="" width="15" height="11"><img src="img/spacer.gif" border=0 alt="" width="15" height="11"><img src="img/spacer.gif" border=0 alt="" width="15" height="11"><img src="img/open.gif" border=0>内部1_1</a><br>
      <a href="sample.htm" target=_blank><img src="img/spacer.gif" border=0 alt="" width="15" height="11"><img src="img/spacer.gif" border=0 alt="" width="15" height="11"><img src="img/spacer.gif" border=0 alt="" width="15" height="11"><img src="img/open.gif" border=0>内部1_1</a><br>
      <a href="sample.htm" target=_blank><img src="img/spacer.gif" border=0 alt="" width="15" height="11"><img src="img/spacer.gif" border=0 alt="" width="15" height="11"><img src="img/spacer.gif" border=0 alt="" width="15" height="11"><img src="img/open.gif" border=0>内部1_1</a><br>
      </div>
      <a href="sample.htm" target=_blank><img src="img/spacer.gif" border=0 alt="" width="15" height="11"><img src="img/spacer.gif" border=0 alt="" width="15" height="11"><img src="img/open.gif" border=0>内部2</a><br>
                                                 </div>
      <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="URL3Parent" class="parent"><a href="#" onClick="expandIt('URL3'); return false" ><img src="img/plus.gif"  border=0>文件夹三</a></div>
      <div id="URL3Child" 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=""><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>
      <div id="KB4Parent" class="parent"><a href="#" onClick="expandIt('KB4'); return false" ><img src="img/plus.gif" border=0>user</a></div>
    <div id="KB4Child" 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=""><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>