jquery - cannot get ajax return and show it -

I use jquery AJAX to make a webmath call, I use Fiddler to debug And it shows that WebMath has returned Jason data

Here's my code:

 Type: "Application / Jason; Charset = UTF-8", URL: "default.aspx / NewUserEvent", data: user_event_data_json, datatype: "Jason", success : Function (New_user_event_id) {$ ("# testingspan"). Text (new_user_event_id.d);}, error: function () {$ ("# testingspan"). Text ("error");}}); ............ ............ ............ & lt; Div id = "testingspan" & gt; & Lt; / Div & gt;   
 I do not know why my browser can not show anything? Are there problems in my code?   
 
 
 'JSON' is not displayed outside each browser box. Most plugins are required Try browsing with Chrome, it can definitely display JSON. This article says more  
  
 Maybe help