function _requestUpdateIssue(evt, callback){
            var field = $(evt.target);
            var fieldName = field.data("fieldName") || field.prop("name");
            var fieldValue = field.data("select2") ? field.data("select2").val() : field.val();

            // Send request to update issueInfo
            $.ajax(vars.urls.massUpdate, {
                "method"  : "post",
                "dataType": "json",
                "data"    : _getUpdateIssueRequestData(fieldName, fieldValue, evt)
            })
            .done(function(res){
                _updateTimeline();

                $yobi.notify(Messages("issue.update." + fieldName), 3000);

                if(field.data("select2")){
                    field.data("select2").val(fieldValue);
                }

                if(typeof callback === "function"){
                    callback(res, fieldName, fieldValue, evt);
                }
            })
            .fail(function(res){
                $yobi.notify(Messages("error.failedTo",
                    Messages("issue.update." + fieldName),
                    res.status, res.statusText));
            });
        }
Send request to update issue info
like as assignee.id, milestone.id and labelIds.

@param evt
@param callback
@private