<select name=year></select>
<select name=month></select>
<select name=date></select>
<select name=clock></select>
<input name=result>

<script>
var arrSel=["year","month","date","clock"];//arrSel定义了要修改的下拉框和xml数据的节点名称
</script>

<xml id=xmldata>
 <xmldata>
  <year value="2000">
   <month value="4">
    <date value="14">
     <clock value="一点" />
     <clock value="三点" />
    </date>
    <date value="17">
     <clock value="一点" />
    </date>
   </month>
   <month value="5">
    <date value="15">
     <clock value="一点" />
     <clock value="四点" />
     <clock value="七点" />
    </date>
   </month>
  </year>
  <year value="2001">
   <month value="7">
    <date value="16">
     <clock value="一点" />
     <clock value="五点" />
     <clock value="九点" />
    </date>
   </month>
  </year>
 </xmldata>
</xml>

<script>
function qswhXml(num){
/******* by qiushuiwuhen(2002-5-17) ********/
 var i,j,arrTemp=[];
 for(i=0;i<num;i++)arrTemp[i]=document.all(arrSel[i]).options[document.all(arrSel[i]).selectedIndex].text
 if(num==arrSel.length){//这里处理最后的数据。
  document.all("result").value="选中了("+arrTemp+")";return;
 }
 with(document.all(arrSel[num])){
  length=0
  var obj=document.all.xmldata.XMLDocument.childNodes[0];
  for(i=0;i<num;i++)obj=obj.selectSingleNode(arrSel[i]+'[@value="'+arrTemp[i]+'"]');
  for(i=0;i<obj.childNodes.length;i++)options[length++].text=obj.childNodes[i].getAttribute("value");
  onchange=new Function("qswhXml("+(num+1)+")");
  onchange();
 }
}
qswhXml(0);
</script>