选择002的时候清空001里的内容,急

Question

清空001？是第2个select吧
document.all.select2.options.length=0

Answer 1

<Script Language="JavaScript">
function loadXML(fileName) { // 定义一个xml dom对象
var xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
xmlDoc.load(fileName);
xmlObj = xmlDoc.documentElement;

for(var i= 0; i<xmlObj.childNodes.length;i++)
if(xmlObj.childNodes(i).getAttribute("id")==document.all.select1.options[select1.selectedIndex].text)
{
document.all.select2.options.length = 0;
for(var j=0; j<xmlObj.childNodes.length;j++)
{
document.all.select2.options.add(new Option(xmlObj.childNodes(i).childNodes(j).text,document.all.select1.options[select1.selectedIndex].text));
}

}
<select name="select1" onChange="loadXML('parseXML.xml')">
<option>0001</option>
<option>0002</option>
<option>0003</option>
<option>0004</option>
</select>
<select name="select2"></select>