ajax+json

 1 <script type="text/javascript">
 2 $(function() {
 3     var jsonObj = {
 4         "name" : "李小",
 5         "age" : 18
 6     };//一个json对象
 7 $("#show").html(jsonObj.name+"的年龄是："+jsonObj.age);
 8 });
 9 </script>
10     <body>
11         <div id="show"></div>
12         <form action="login.action" method="post">  
13             <div>
14                 用户名：
15                 <input name="username" type="text" value="" id="username"
16                     onblur="chkName()" />
17                 <span id="msg"></span>
18             </div>
19 
20             <input type="submit" value="提交" />
21         </form>
22     </body>

 1 <script type="text/javascript">
 2 $(function() {
 3 var students = [ {数组，数组里放的是json对象
 4         "name" : "李小1",
 5         "age" : 18
 6     }, {
 7         "name" : "李小2",
 8         "age" : 28
 9     }, {
10         "name" : "李小3",
11         "age" : 38
12     } ];//数组:元素是json对象*/
13 for ( var s in students) {
14         $("#show").append(
15                 students[s].name + "的年龄是：" + students[s].age + "<br/>");
16     }
17 });
18 </script>
19 <body>
20         <div id="show"></div>
21         <form action="login.action" method="post">  
22             <div>
23                 用户名：
24                 <input name="username" type="text" value="" id="username"
25                     onblur="chkName()" />
26                 <span id="msg"></span>
27             </div>
28 
29             <input type="submit" value="提交" />
30         </form>
31     </body>