AJAX实现三级联动
    <%@ page contentType = "text/html; charset=GBK"  import="java.util.*,com.wehave.hyerp.procurement.domain.Cgsqd"%>
<%@ taglib uri="struts-html" prefix="html" %>
<%@ taglib uri="struts-logic" prefix="logic" %>
<%@ taglib uri="struts-bean" prefix="bean" %>
<html>
    <head>
        <title> </title>
        <link rel = "stylesheet" type = "text/css" href = "../css/olstyle.css">   
        <SCRIPT type="text/javascript">
        var req;
        window.onload=function(){
        }       
        function Change_Select()
        {
            var zhi=document.getElementById('m_gykfwzlbb_lbbm').value;
            var url="sqdSelect.go?method=getSkill&id="+zhi;
            if(zhi=="0"){
                alert("请选择您要察看的信息");
                   return;
            }else{
                if(window.XMLHttpRequest)
                {
                    req=new XMLHttpRequest();
                }else if(window.ActiveXObject)
                {
                    req=new ActiveXObject("Microsoft.XMLHTTP");
                }               
                if(req)
                {
                    req.open("GET",url,true);
                    req.onreadystatechange=callback;
                    req.send(null);
                }
            }
        }       
        function Change_Select2()
        {
            var zhi=document.getElementById('m_lb