UI Dialog Error: b("<div></div>").addClass("ui-widget-overlay") is undefined

UI Dialog Error: b("<div></div>").addClass("ui-widget-overlay") is undefined

I have the below code for my a Dialog box for a which contains a dropdown field
  1. KPMS.ServiceRequests.Status = {
  3. showOptions : function(requestId, userId, requestType) {
  4. var url = BASE_URL+'service_requests/status_options/';
  6.         $("#dialog-modal").dialog("destroy");
  7. $("#dialog-modal").load(url, {"request_id": requestId, "user_id": userId}).dialog(
  8. {
  9. modal: true,
  10. title: "Update Status",
  11. buttons: {
  12. Cancel : function() {
  13. $(this).dialog('close');
  14. },
  15. Update: function() {
  16. KPMS.ServiceRequests.Status.update(requestId, userId, requestType);
  17. }
  18. }
  19. }
  20. );
  21. }

  23. }

There is an anchor tag to populate the Dialog 

  1. <a onclick="KPMS.ServiceRequests.Status.showOptions(9, 11, 'SR'); return false;" title="Update status" href="http://localhost/kitco/pms/#9"><img alt="[E]" title="Update" src="http://localhost/kitco/pms/images/edit.png"></a>

My problem is When i click the clink for the first time the dialog box is populating properly.
Then i close the dialog using the cancel butto, then again clicked the link to open the dialog and closed it.
For the third click on the link I'm getting the below Javascript error, and Dialog box is not opened

  1. Error: b("<div></div>").addClass("ui-widget-overlay") is undefined
  2. Source File: http://localhost/kitco/pms/js/jquery-ui-1.8rc3.custom.min.js
  3. Line: 199

How to solve this error?