如何删除前面的结点 - 黑马程序员技术交流社区

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>7.html</title>
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="this is my page">
<meta http-equiv="content-type" content="text/html">
</head>
<body>
<select name="province" id="province">
<option value="">请选择</option>
<option value="湖北省">湖北</option>
<option value="江苏省">江苏</option>
<option value="湖南省">湖南</option>
</select>
<select name="citys" id="citys">
<option value="">请选择。。。</option>
</select>
</body>
<script type='text/javascript'>
var n = 0; //删除结点的标记
window.onload = function() {
document.getElementById("province").onchange = function() {
//alert("xxx");
//加载xml文件
var flag;
var xmlDoc = parseXML("7.xml");
var proElements = xmlDoc.getElementsByTagName("province");
var proElement = document.getElementById("province");
var opNodes = proElement.childNodes;
for(var i = 0; i < opNodes.length; i++) {
if(opNodes[i].selected) {
//alert(i); //3 5 7
if(i == 3) {
flag = 0;
break;
}
else if(i == 5) {
flag = 1;
break;
}
else if(i == 7) {
flag = 2;
}
else
return false;
}
}
/**** 显示湖北省的城市 *******/
/*
* <province name="湖北省">
<city>武汉</city>
<city>孝感</city>
<city>仙桃</city>
<city>襄樊</city>
</province>
*/
var city = proElements[flag].childNodes;
var citysElement = document.getElementById("citys");
//
//printNodeMessage("NODE",huBei[1].firstChild);
for(var i = 0; i < city.length; i++) {
//1
var opNode = document.createElement("option");
//2
opNode.setAttribute("value", city[i].firstChild.nodeValue);
//3
var textNode = document.createTextNode(city[i].firstChild.nodeValue);
//4
opNode.appendChild(textNode);
//5
citysElement.appendChild(opNode);
}
}
}
/*****/
function printNodeMessage(nodeName,node) {
alert(nodeName + ":" + "nodeVale:" + node.nodeValue + " nodeTyoe:" + node.nodeType + " nodeName:" + node.nodeName);
}
/*****/
function parseXML(filename){
try //Internet Explorer
{
xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
}
catch (e) {
try //Firefox, Mozilla, Opera, etc.
{
xmlDoc = document.implementation.createDocument("", "", null);
}
catch (e) {
alert(e.message);
return;
}
}
//关闭异步加载
xmlDoc.async = false;
//加载xml文档
xmlDoc.load(filename);
return xmlDoc;
}
</script>
</html>

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