Just what I've noticed at first sight 'c2dictionary' => 'true', it should be 'c2dictionary' => true. I'm not sure if it's a mistake, it might work if C2 checks with == but will fail if it checks with ===.
Anyway First of all I suggest to keep database credentials in some separate file. Also using some ORM DB library will give you better protection from mysql injection and your code will look much more tidy if you use some separate models for business operations, retrieving data etc.
You also did not set header to JSON application. If you just send JSON, you should do it.
Now what is exactly not working? Have you checked if AJAX.LastData has any content or you've checked the dictionary content after AJAX load?
Is there a problem with connecting to PHP?
Retrieving any data?
Filling dictionary?
PHP gives any error?
Try to provide as much info as possible whenever you ask for help.