On other iterations, it increments the retry counter. Overrides the error callback for current request to be able to call the AJAX request again when it timeouts. Chaining jQuery Ajax Calls. Starting with version 1.5, jQuery has provided Deferred Objects to make working with asynchronous functions a little easier.What I wanted was to define a sequence of Ajax requests without having to deal with nested callbacks. jQuery JSONP Callback not firing. Thinking in AngularJS if I have a jQuery background?Ive tried this with the JSONP callback handler passed into the "success" parameter for the Ajaxrunning the script in the body, not dom load. head will work too. function must be defined in the global namespace.) jQuery.