ajax的异步提交到action，成功插入数据库在页面返回结果

jsp代码：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

注册
 function checkUserName(obj){ var username = obj; var checkUserNameResult = document.getElementById("checkUserNameResult"); if(username.trim().length==0){ checkUserNameResult.innerHTML = "*用户名不能为空"; obj.focus(); }else{ checkUserNameResult.innerHTML = ""; } } 
 function checkPassword(obj){ var password = obj; var checkPasswordResult = document.getElementById("checkPasswordResult"); if(password.trim().length==0){ checkPasswordResult.innerHTML = "*密码不能为空"; obj.focus(); }else{ checkPasswordResult.innerHTML = ""; } } 

 function checkrePassword(obj){ var repassword = obj; var checkrePasswordResult = document.getElementById("checkrePasswordResult"); if(repassword.trim().length==0){ checkrePasswordResult.innerHTML = "*确认密码不能为空"; obj.focus(); }else{ checkrePasswordResult.innerHTML = ""; } }

</head>

<body>
    <h1>用户注册</h1>
    <form>
    <div>
    账&nbsp;&nbsp;号：<input type="text" name="username"  onblur="checkUserName(this.value);"/>
                        <span  id="checkUserNameResult" style="color: red "></span>
                        <br/><br/>
    密&nbsp;&nbsp;码：<input type="password" name="password" id="pwd1" onblur="checkPassword(this.value);"/>
                        <span id="checkPasswordResult" style="color: red "></span>
                        <br/><br/>
    确认密码：<input type="password" name="repassword" id="pwd2" onblur="checkrePassword(this.value);"/>
                        <span id="checkrePasswordResult" style="color: red "></span>
                        <br/><br/>
    性&nbsp;&nbsp;别：<input type="radio" name="sex" value="man" checked="checked" />男
                        <input type="radio" name="sex" value="woman"  />女
    <br/><br/>
    爱&nbsp;&nbsp;好：<input type="checkbox" name="hobby" value="sport"/>运动
                        <input type="checkbox" name="hobby" value="sport"/>上网
                        <input type="checkbox" name="hobby" value="sport"/>看书
                        <input type="checkbox" name="hobby" value="sport"/>听歌
                        <input type="checkbox" name="hobby" value="sport"/>睡觉
    <br/><br/>
    年&nbsp;&nbsp;龄：<input type="text" name="age" /><br/><br/>
    出生日期：<input type="text"/><br/><br/>
    备&nbsp;&nbsp;注：<textarea name="word" cols=50 rows=10></textarea><br/><br/>    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<input type="submit" value="注册" onclick="return checkpasswd()"/>&nbsp;&nbsp;
    <input type="reset" />
    </div>
    </form>
</body>
</html>

ajax和action如何写啊，才开始学习web，求大神教教

<---form id="from1"><-/form>//form定义一个id
<--input type="button" value="注册" onclick="checkpasswd()"/->//请求type用button
function checkpasswd(){
$("#from1").ajaxSubmit({
url:ulr，//你的请求地址
type:"post",//你的请求类型
dataType:"json"，
data：{}，
success:function(result){
if(result.status){
//成功
alert(resylt.msg);
}else{
//失败
alert(resylt.msg);
}
}
});
}
后台action返回方式
Map map=new HashMap();
String msg="成功";
boolean status=true;
map.put("msg",msg);
map.put("status",status);
//map转换成json
response.getWriter().write(JSONObject.fromObject(map).toString);