日期:2014-05-17  浏览次数:20783 次

如何用Ajax做下拉框
<body>
  <form method="post" action="getAll">
  <table border="1" align="center" width="50%">
  <tr>
  <td colspan="2"><strong>影院查询与发布系统</strong></td>
  </tr>
 
  <tr>
  <td>电影名称:</td>
  <td><input type="text" name="fN"></td>
  </tr>
 
  <tr>
  <td>电影类型:</td>
  <td>
  <select>
  <option value="0">全部</option>
  </select>
  </td>
  </tr>
 
  <tr>
  <td>主演:</td>
  <td><input type="text" name="fA"></td>
  </tr>
 
  <tr>
  <td>导演:</td>
  <td><input type="text" name="fD"></td>
  </tr>
 
  <tr>
  <td>电影名称:</td>
  <td><input type="text" name="fN"></td>
  </tr>
 
  <tr>
  <td>价格:</td>
  <td><input type="text" name="mi">至<input type="text" name="mx"></td>
  </tr>
 
  <tr>
  <td>查询:</td>
  <td><input type="submit" value="提交查询内容"/></td>
  </tr>
 
  </table>
  </form>
  </body>
我要怎么写方法,来根据我所写的内容来查询。就是说,如果我只输个电影名称,也能查到结果,我全部输人了就能更精确的查找
另外我想电影类型是用AJax来做的求指导,给点提示,不一定要告我代码怎么写

------解决方案--------------------
<%@ page language="java" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<html>
<head>
<base href="<%=basePath%>">
<title>
注册
</title>
<script type="text/javascript">

var xmlHttp; 
function createXMLHttpRequest() {

if (window.XMLHttpRequest) { 
xmlHttp = new XMLHttpRequest(); 
} else if (window.ActiveXObject) { 
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP"); 


if(!xmlHttp){
alert("Error Initializing XMLHttpRequest!");
}
}
 
function UserNameCheck() {

createXMLHttpRequest();

xmlHttp.onreadystatechange = callback;

var username = document.getElementById('username').value;
//var url = "index?user_name=" + username;

var url="user/index";
//xmlHttp.open("get", url, true);
xmlHttp.open("post",url,true);
//xmlHttp.send(null);
xmlHttp.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
xmlHttp.send("user_name=" + username);

}


function callback() {



if (xmlHttp.readyState == 4)