ajax提交，后台老板没法写代码

<br />$(document).ready(function(){  <br />        //post()方式  <br />        $('#test_post').click(function (){   <br />            $.post(  <br />                'ajax.php',  <br />                {  <br />                     		id:$("#id").val(),                   <br />                },  <br />                function (data) { //回调函数  <br />                    var myjson='';  <br />                    eval('myjson=' + data + ';');  <br />					alert(data);<br />                    $('#result').html("ID为:" + myjson.username);  <br />                }  <br />            );  <br />        });  <br />       <br />});  <br />

<br />  $a = $_POST["id"];	   <br />		 $conn  = mysql_connect("localhost","root",""); <br />		 $my_db = mysql_select_db("demo",$conn);<br />		 $sql="select * from demo where id = $a";<br />	    $result = mysql_query($sql, $conn);<br />		$userInfo = mysql_fetch_assoc($result);             <br />	<br />	    print_r($userInfo);<br />	//   echo $a;<br />