Select 二级下拉联动的实现
1、js代码
function callAjax(url, postParams) {
beforeInvoke();
createXMLHttpRequset();
xmlHttpRequest.open("post",url,true);
xmlHttpRequest.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
xmlHttpRequest.onreadystatechange=function() {
if(xmlHttpRequest.readyState == 4) {
finishInvoke();
if(xmlHttpRequest.status == 200) {
var returnValue = xmlHttpRequest.responseText;
backInvoke(returnValue);
}
}
};
xmlHttpRequest.send(postParams);
}


2、html: