Ajax简单登录GET方式认证

<script type="text/javascript">

var xmlHttp;

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

//发送请求函数
function sendRequest(url){
 
 createXmlHttp();
 xmlHttp.open("GET",url,true);
 xmlHttp.onreadystatechange=processResponse;
 xmlHttp.send(null);
}

//处理返回信息函数

function processResponse(){
 
 if(xmlHttp.readyState ==4){
  if(xmlHttp.status ==200){
   var msg =xmlHttp.responseText;
   
   alert(msg);
  }
 }
 
}

function userCheck(){
 
 var uname=document.myForm.userName.value;
 var pwd=document.myForm.userPwd.value;
 if(uname ==""){
  alert("用户名不允许为空");
  document.myForm.userName.focus();
  
  return false; 
 }else{
  sendRequest('userLogin?uname='+uname+ '&pwd='+pwd);
 }
}

 

</script>

 

 

<form action="" method="post" name ="myForm">
     用户名：<input type ="text" name="uname"><br>
     密码：<input type ="password" name="pwd"><br>
     
     <input type ="button" value="登录" onclick="userCheck()">
    </form>