JQuery初探---Jquery/Ajax

<form id="testId" method="post">
<center>
Input ur name Please:   <input name="username" id="username" /><br/>
<a id="isvalid"></a>
Input ur password:   <input name="password" id="password" /><br/>
QQ:   <input name="qq" id="qq" /><br/>
<input type="button" value="submit" onclick="go();" />
</center>
</form>

<script type="text/javascript">
function go(){
alert("===提交表单===");
$.ajax({
cache: true,
type: "POST",
url: 'b.jsp',
data:$('#testId').serialize(),// 你的formid
async: false,
error: function(XMLHttpRequest, textStatus, errorThrown) {
alert(XMLHttpRequest.status);
alert(XMLHttpRequest.readyState);
alert(textStatus);
},
success: function(data) {
//alert("success");
$.messager.confirm('1','2','3');
alert(data);
}
});
}
</script>

<%@page contentType="text/html;charset=UTF-8"%>
<%
System.out.println("====b.jsp======");
System.out.println(request.getParameter("username"));
System.out.println(request.getParameter("password"));
System.out.println(request.getParameter("qq"));
if( request.getParameter("username").equals("hdb") && request.getParameter("password").equals("123456") ){
response.getWriter().println("恭喜您登陆成功");
}else{
response.getWriter().println("用户名或密码不正确");
}
%>