js xml generates cascading drop-down box code_javascript skills

When you need to select it by default, define a variable var cityId=city id
The following is the js code

Copy the code The code is as follows:

function readxml() {
var XmlDoc = null;
if (window.ActiveXObject) {
XmlDoc = new ActiveXObject("Microsoft.XMLDOM");
XmlDoc .async = false;
XmlDoc.load(path "/web/common/regions.xml");
browse = "ie";
} else if (document.implementation
&& document. implementation.createDocument) {
xmlDoc = document.implementation.createDocument('', '', null);
xmlDoc.load("regions.xml");
browse = "ff";
} else {
alert('Not compatible with this browser!');
}
var root = XmlDoc.documentElement;
// Get the province node below the root node
var provinces = root.childNodes;
var province = document.getElementByIdx_x_x("province");
var cities = document.getElementByIdx_x_x("regId");
for ( var i = 0; i < ; provinces.length; i ) {
// Get the value of the name attribute of the province node
var name = provinces[i].getAttribute("name");
// Create an option
var opt = document_createElement_x_x("option");
// Add text to option
opt.a(document_createTextNode(name));
// Add to parent node
if(cityId!= null&&cityId!=""){
var cities=provinces[i].childNodes;
for(var j=0;jif(citys[j].getAttribute ("id")==cityId){
opt.selected="selected";
for ( var j = 0; j < cities.length; j ) {
// Create an option
var opt1 = document_createElement_x_x("option");
opt1.value = cities[j].getAttribute("id");
// Add text for option
opt1.a(document_createTextNode(citys [j]
.getAttribute("name")));
// Add to parent node
if(citys[j].getAttribute("id")==cityId){
opt1.selected="selected";
}
cities.a(opt1);
}
}
}
}
province.a(opt);
}
province.onchange = function() {
var pce = document.getElementByIdx_x_x("province");
var opts = pce.options;
var opt1 = opts[pce.selectedIndex] ;
var name = opt1.innerText;
for ( var i = 0; i < provinces.length; i ) {
// Get the value of the name attribute of the province node
var name1 = provinces[i].getAttribute("name");
if (name == name1) {
cities.length = 1;// Clear every time it changes
var pros = provinces[i] ;
var cities = pros.childNodes;
for ( var j = 0; j < cities.length; j ) {
// Create an option
var opt1 = document_createElement_x_x("option" );
opt1.value = cities[j].getAttribute("id");
// Add text for option
opt1.a(document_createTextNode(citys[j]
.getAttribute(" name")));
// Add to parent node
cities.a(opt1);
}
}
}
}
}

The following is the xml structure

Copy the code The code is as follows: