JSP与JavaScript实现级联菜单的完整代码示例

<%@ page import="java.util.Date,yava.fileapp.*,java.sql.*;"
contentType="text/html;charset=GB2312" pageEncoding="GB2312"
  %>
<style>
.f9{ font-size:9pt; }
.bgc{ background-color:#AECAF9; color: #0033FF }
.buttons{font-family:Arial; font-size:13px; font-weight:bold; background-color:#6796E4; color:white; border-top: solid 2px #AACAFB;
border-bottom: solid 1px #4E7DC1;
border-left: solid 1px #AECAF9;
border-right: solid 1px #5679BD;
padding:1px;
margin:0px;}
</style>
<SCRIPT LANGUAGE="JavaScript">
  <!--
function rv()
  {
var val="";
for(i=0;i<combo_box.list2.length;i++){
val+=","+combo_box.list2[i].value;
    }
if(val.charAt(0)==","){
val=val.substr(1,val.length);
    }
opener.form1.frecname.value=val;
self.close();
  }
<!--
 </SCRIPT>
 <body leftmargin="0" topmargin="0" marginwidth="0" marginheight="0">
 <jsp(SUN企业级应用的首选):useBean id="user" scope="session" class="yava.fileapp.UserBean" />
 <%
 CDataSource ds=new CDataSource(); //数据联结Bean实例
 java.sql.Connection conn=ds.getConnection();
 java.sql.Statement stmt=null;
 java.sql.ResultSet rs=null;
 CDataCheck dc=new CDataCheck();
 %>
 
<%
 String sqlu="SELECT t1.fno, t1.fname, t2.fname AS fdept FROM tuser t1 LEFT OUTER JOIN TDept t2 ON t1.fdept = t2.fno order by t2.fname";
 stmt=conn.createStatement();
 rs=stmt.executeQuery(sqlu);
 %>
 <script language=Javascript>
 arr = new Array();
 <% int temp=0;
 while(rs.next())
 {
 %>
 arr[<%=temp%>]=new Array("<%=rs.getString("fname")%>","<%=rs.getString("fdept")%>");
 <%
 temp = temp + 1;
 }
 %>
 temp=<%=temp%>;
 function ChangeLocation(id){ 
 document.combo_box.city.length=0; //初始化第2级菜单的长度，下标从0开始 
 var i = 0; 
 document.combo_box.city.options[0]=new Option(-------,); 
 for(i=0;i<temp;i++){ 
 if(arr[i][1]==id){//如果相等，证明在第2级里面有输入第1级组织的子集,arr[总数目][部门] 
 document.combo_box.city.options[document.combo_box.city.length] = new Option(arr[i][0], arr[i][0]); 
 } 
 } 
 } 
 </script>
<form name="combo_box">
 <table border="0" cellspacing="0" cellpadding="0" height="210" width="59">
 <tr height="24">
 <td bgcolor="#336699" class="buttons" align=center><font color=#ffffff>部门选择</font></td>
 <td bgcolor="#336699" class="buttons" align=center><font color=#ffffff>人名选择</font></td>