Ajax对Struts操作的调用不起作用

Question

我正在尝试使用Ajax 1.9和struts1.3从服务器获取最新的输出。下面的代码不起作用。

function doAjaxPost()
        {               
            var aRequest = $.ajax({
                  type: "POST",
                  url: "/UserAction.do",
                  data: { user: p }
             });

            aRequest.done(function(msg)
             {
                  alert( "You have successfully received output!" );
                  $('#ajaxOutput').html(msg);
                  setTimeout(doAjaxPost(),15000);
             });

            aRequest.fail(function(jqXHR, textStatus)
             {
                  alert( "Problem in getting output (" + textStatus + ")." );
             });
        }


<input type="button" name="start" value="Start" onclick="doAjaxPost();">
<div id="ajaxOutput"></div>

在struts-config.xml中，我有表单定义＆amp;动作映射如下

<form-bean name="UserForm" type="com.admin.ui.beans.UserFormBean" />

<action
         path="/UserAction"
         type="com.admin.ui.action.UserAction"
         name="UserForm"
         scope="request"
         validate="false">
         <forward name="success" path="/User.jsp"/>
         <forward name="error" path="/errorPage.jsp"/>
</action>

我做错了什么，请指导我。非常感谢您的帮助！提前谢谢。