WGA.ajax.request(method, uri, data, cb [, headers])
Executes an HTTP request via AJAX
The call registers a callback function as parameter "cb" which gets called once the response returns with data. This function receives the XMLHTTPRequest object that executed the request as single parameter, so it can read the returned data and react on it.
The HTTP method to execute, for example "GET" or "POST"
The URI to send the request to
Some data to be sent with a POST request. May be any object type supported by the send() method of XMLHTTPRequest as parameter "data". Specify null to not use it.
The callback function
An object containing properties which will be set as HTTP headers on the request. Property names are used as header names, values as header values.