Ajax not returning data after post call

Ajax not returning data after post call

I know there are tons of these questions out there but everything I try seems to fail. Im just sending a simple ajax call and expecting to get something back. Instead the call succeeds but I get no data back. Ideas why?

the javascript:
  2. jQuery(document).ready(function() {
  3. if(jQuery('#statesel').length) {
  4. var dataString;
  6. dataString = "nonce=" + dynoselect.post_dyno_select_nonce + "&tbl=state";
  7. jQuery.ajax({
  8. type: "POST",
  9. url: dynoselect.ajaxurl,
  10. dataType: "json",
  11. data: dataString,
  12. success: function(result) {
  13. alert(result.test);
  14. }
  15. });
  16. }
  17. });
the php:
  2. <?php
  3. function dyno_select() {
  4. $result['test'] = "HELLO";
  5. echo json_encode($result);
  6. }
  7. ?>