javascript级联:动态生成javascript代码 下拉条的级联效果

怎样动态生成javascript代码:
带下拉条那种,
首先, 主表bookinfo有个字段是booktype, 不 类型,
从表booktype 有个字段id , 也是 类型.
表bookinfo中字段booktype是表booktype外键.
我想让他们两者级联.

实现代码是这样:
<%@ page contentType="text/html; char=gb2312" language="java"

import="java.sql.*" errorPage="" %>
<%@ page import="java.util.*" %>

<%@ page import="com.deng.library.ActionForm.BookTypeForm" %>
<%@ page import="com.deng.library.dao.BookTypeDAO" %>


<%
List<BookForm> bookModyQuery = (List<BookForm>)

request.getAttribute("bookModyQuery"); //返回类型为List
%>

<% for( i = 0; i<bookModyQuery.size; i){
BookForm bookForm = (BookForm)bookModyQuery.get(i);
%>

<%
String str = null;
BookTypeForm bookTypeForm = null;
BookTypeDAO bookTypeDAO = BookTypeDAO;
List<BookTypeForm> list = (List<BookTypeForm>)

bookTypeDAO.bookTypeQuery(str);
(listnull || list.isEmpty){
out.prln("<script language='javascript'>alert('请先

输入图书类型!');history.back(-1);</script>");
}{
Iterator<BookTypeForm> it = list.iterator;
while(it.hasNext){
bookTypeForm = (BookTypeForm)it.next;
%>
<option value="<%=bookTypeForm.getId %>"<%

(bookForm.getTypeIdbookTypeForm.getId) out.prln("selected");

%>><%=bookTypeForm.getTypeName %></option>
<%
}
}
%>


<%
}
%>

注意到:
<%(bookForm.getTypeIdbookTypeForm.getId) out.prln

("selected");
主要是这句代码.
希望此贴对来访者有用.代码可能有点乱. 是在我本人项目上.来访者如有疑问,可以留言.

延伸阅读

• 2008-12-25-- 级联下拉列表:JavaScript XML实现两级级联下拉列表