function getAjaxData(urlstr, callback_func, options){
 var myurl = AJAX_HEADER + urlstr + AJAX_TAIL;
 var isAsync = true;//初始化是否同步的属性设置
 var nTimeout = AJAX_TIMEOUT;//初始化请求超时的数据
 var errorCallback = null;
 //利用JSON对象options来修改默认初始化的属性，这样一个参数可以设置多个属性
 if (options)
 {
  if (options.sync) //sync这个参数就是JSON的对象
  {
   isAsync = (options.sync === true) ? false : true;
  }
  if (options.timeout)
  {
   nTimeout = parseInt(options.timeout);
   if (isNaN(nTimeout))
    nTimeout = AJAX_TIMEOUT;
  }
  errorCallback = options.errorCB;
 }
 if ($.browser.mozilla)
 {
  try
  {
   //netscape.security.PrivilegeManager.enablePrivilege("UniversalBrowserRead");
  }
  catch (exception)
  {
   log.error(exception);
  }
 }
 $.ajax({
  async: isAsync,
  //cache: false,
  type: "GET",
  timeout: nTimeout,
  url: myurl,
  //dataType: ($.browser.msie) ? "text" : "xml",
  error: function(XMLHttpRequest, textStatus){
   try
   {
    if (jQuery.isFunction(errorCallback))
    {
     errorCallback(XMLHttpRequest, textStatus);
    }
    log.error("MAIN : getAjaxData(" + myurl + ") error.");
    log.error("MAIN : XMLHttpRequest.readyState = " + XMLHttpRequest.readyState);
    log.error("MAIN : XMLHttpRequest.status = " + XMLHttpRequest.status);
    log.error("MAIN : textStatus " + textStatus);
   }
   catch (exception)
   {
    log.error(exception);
   }
  },
  success: function(data){
   log.debug("MAIN : getAjaxData(" + myurl + ") sucess.");
   log.trace(data);
   var xml;
   if (typeof data == "string" || typeof data == "number")
   {
    if (!window.ActiveXObject)
    {
     var parser = new DOMParser();
     xml = parser.parseFromString(data, "text/xml");
    }
    else
    {
     //IE
     xml = new ActiveXObject("Microsoft.XMLDOM");
     xml.async = false;
     xml.loadXML(data);
    }
   }
   else
   {
    xml = data;
   }
   if (typeof callback_func == "function")
   {
    callback_func($(xml));
   }
   else
   {
    log.error("callback_func is undefined or not a function");
   }
  }
 });
}
getAjaxData("api/monitoring/status", function($xml){
  var wlan_ret = xml2object($xml);
  if(wlan_ret.type == "response")
  {
   monitoring_status = wlan_ret.response;
   setCurrrentUserHTML();
  }
},
{
  sync:true //通过JSON传递多个数据，防止数据冗余，这里类似于配置信息
});

function testJSON(JSON){
 alert(JSON.name);
 alert(JSON.age);
 alert(JSON.id);
}
testJSON({name:"huangbiao",
  "age":23,
  "id":1});