tornadoweb Access-Control-Allow-Origin jquery POST -

i want enable cors request via jquery using post request handler. below tornado request , jquery

class basehandler(tornado.web.requesthandler):     def set_default_headers(self):         self.set_header('access-control-allow-origin', '*')         self.set_header('access-control-allow-methods', 'post, get, options')         self.set_header('access-control-max-age', 1000)         #self.set_header('access-control-allow-headers', 'origin, x-csrftoken, content-type, accept')         self.set_header('access-control-allow-headers', '*')         self.set_header('content-type', 'application/json') 

but after calling:

$.ajax({             type: 'post',             url: _url,                   /*                   beforesend : function(x) {                 if (x && x.overridemimetype)                     x.overridemimetype("application/j-son;charset=utf-8");             },*/             beforesend: function ( xhr ) {                 xhr.setrequestheader('content-type', 'application/json');                 xhr.setrequestheader('access-control-request-method', 'post');                 xhr.setrequestheader('access-control-request-headers', 'x-requested-with');                 xhr.withcredentials = true;             },               data : _data,                         datatype: 'json',             contenttype: 'application/json',             success:  function (data) {                 alert(data);             },             error: function (err) {                 console.log("ajax response: "+resp+" json="+json.stringify(resp));             }         }); 

and sending:

i receive: reload page source "my post url goes here". ideas catch?