日期:2014-05-20  浏览次数:20719 次

关于上个问题的继续 为什么我通过Ajax返回来的值是true 我必须点击2次登录按钮才能登陆成功
index.jsp
------------------------------------

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>欢迎页面</title>
<style type="text/css">
body {
font-family: 黑体;
font-size: 20px;
font-weight: bold;
}
</style>
<script type="text/javascript">
var flag=false;
alert(flag);
var xmlhttp;
function checked() {
var userInput = document.getElementById("userInput").value;
var managerId=document.getElementById("managerId").value;
var managerPWD=document.getElementById("managerPWD").value;
if(userInput=="")
{
document.getElementById("show").innerHTML="<font color='red'>您没有选择登录功能</font>";
flag= false;
return flag;
}
if(userInput!=1 && userInput!=2 )
  {
  document.getElementById("show").innerHTML="<font color='red'>您输入的不正确</font>";
flag= false;
return flag;
  }
if(managerId=="")
{
document.getElementById("managers").innerHTML="<font color='red'>管理员账号不能为空</font>";
flag= false;
return flag;
}

if(managerPWD=="")
{
document.getElementById("managerssPWD").innerHTML="<font color='red'>管理员密码不能为空</font>";
flag= false;
return flag;
}
  send_httpRequest();
  return flag;
}



function createHttpRequest() //创建XMLHttpRequest对象
{
if(window.XMLHttpRequest)
{
xmlhttp =new XMLHttpRequest();
}else if(window.ActiveXObject)
{
xmlhttp =new ActiveXObject("Microfost.XMLHTTP");
}
}

function send_httpRequest()
{
var managerId=document.getElementById("managerId").value;
var managerPWD=document.getElementById("managerPWD").value;
createHttpRequest();
xmlhttp.open("post","index?managerId="+managerId+"&&managerPWD="+managerPWD,true);
xmlhttp.onreadystatechange=Callback;
xmlhttp.send(null);
}
function Callback()
{
if(xmlhttp.readyState==4)
{
if(xmlhttp.status==200)
{
var text = xmlhttp.responseText;
alert("text"+text);
if(text=="true")
{
flag = true;
alert(flag);
}
else
{  
flag = false;
alert(flag);
}
}
}
}
</script>
</head>
<body style="background-color: #999">
<div style="padding-top: 100px;" align="center">
<form action="showManager.jsp" onsubmit="return checked()"
method="post">
<table width="1024" height="223">
<tr>
<td colspan="2" align="center">
欢迎你进入商品管理系统
</td>
</tr>
<tr>
<td colspan="2">
&nbsp;

</td>
</tr>
<tr>
<td colspan="2" align="center">
1.商品购物系统
</td>
</tr>
<tr>
<td colspan="2" align="center">
2.商品管理系统