1 <!DOCTYPE html>
2 <html>
3 <head>
4 <meta charset="UTF-8">
5 <title>Insert title here</title>
6 <script type="text/javascript">
7 //ajax引擎对象
8 var xmlHttpRequest=null;
9 try {
10 xmlHttpRequest=new ActiveXObject("Msxml2.XMLHTTP");
11 } catch (e) {
12 //alert("非IE浏览器");
13 try {
14
15 xmlHttpRequest = new XMLHttpRequest();
16 } catch (e) {
17 xmlHttpRequest = new ActiveXObject("Microsoft.XMLHTTP");
18 }
19
20 }
21
22
23 function checkUserName(t){
24 var userName=t.value;
25 var reqUrl="data.do?userName="+userName;
26 //监听第二步 绑定ajax引擎的监听对象
27 var passwd="passwd="+userName;
28
29
30 alert("test");
31 xmlHttpRequest.onreadystatechange=function(){
32 alert(xmlHttpRequest.readyState);
33 if(xmlHttpRequest.readyState==4 && xmlHttpRequest.status==200){
34 //alert(xmlHttpRequest.responseText);
35 }
36 }
37 //3，绑定提交地址open(method,url,isAsynchronous)
38 xmlHttpRequest.open("post",reqUrl,true);
39
40 //如果使用POST请求发送数据，需要设置请求头
41 xmlHttpRequest.setRequestHeader('Content-typ','application/x-www-form-urlencoded');
42
43 //4,发送请求
44 xmlHttpRequest.send(passwd);
45 }
46 </script>
47 </head>
48 <body>
49 用户名<input type="text" id="userName" onchange="checkUserName(this)" >
50 密码<input type="password" id="passwd" onchange="checkUserName(this)" >
51 </body>
52 </html>
