if (pendingajax) {

          pendingajax.abort();

          pendingajax = undefined;

      }

      pendingajax = ajaxGET(pyroutes.url('pullrequest_repo_info', {"repo_name": repo_name}),

          function(data){

              pendingajax = undefined;

              $('#other_repo_desc').html(data.description);

              // replace options of other_ref with the ones for the current other_repo

              $other_ref.empty();

              for(var i = 0; i < data.refs.length; i++)

              {

                var $optgroup = $('<optgroup/>').prop('label', data.refs[i][1]);

                var options = data.refs[i][0];

                var length = options.length;

                for(var j = 0; j < length; j++)

                {

                  $optgroup.append($('<option/>').text(options[j][1]).val(options[j][0]));

                }

                $other_ref.append($optgroup);

              }

              $other_ref.val(data.selected_ref);

              $("#other_ref").select2({

                  dropdownAutoWidth: true

              });

              $other_ref.prop('disabled', false);

              loadPreview();

          });

  };

  var loadPreview = function(){

      //url template

      var url = "${h.url('compare_url',

                         repo_name='__other_repo__',

                         org_ref_type='rev',

                         org_ref_name='__other_ref_name__',

                         other_repo='__org_repo__',

                         other_ref_type='rev',

                         other_ref_name='__org_ref_name__',

                         as_form=True,

                         merge=True,

                         )}";

      var org_repo = $('#pull_request_form #org_repo').val();

      var org_ref = $('#pull_request_form #org_ref').val().split(':');

      ## TODO: make nice link like link_to_ref() do