this is my code : the warning come when no data retrieve from database .. how to fix this?.. i do not know how to change for multiple array.

```
foreach ($users_id_array[$region_chart2][$country_chart2] as $key) {

                $query_diff2 = "SELECT ut_lp_marks.obj_id, object_data.title, read_event.spent_seconds, " .
                        "read_event.read_count, ut_lp_marks.status, ut_lp_marks.percentage, ut_lp_marks.u_comment FROM ut_lp_marks ".
                        "LEFT JOIN object_data ON (object_data.obj_id = ut_lp_marks.obj_id) ".
                        "LEFT JOIN read_event ON (read_event.obj_id = object_data.obj_id AND read_event.usr_id = ut_lp_marks.usr_id) ".
                        "WHERE ut_lp_marks.usr_id=$key AND object_data.type = 'crs'";

                     $result_diff2 = mysql_query($query_diff2);

                            while($rec_diffcourse2 = mysql_fetch_assoc($result_diff2))
                            {

                                 if ($rec_diffcourse2['status'] == 0) {

                                        $total_diffna1++;
                                    }
                                    if ($rec_diffcourse2['status'] == 1) {
                                        $total_diffinprogress1++; 
                                    }
                                    if ($rec_diffcourse2['status'] == 2) {
                                        $total_diffpassed1++;
                                    }
                                    if ($rec_diffcourse2['status'] == 3) {
                                        $total_difffailed1++;
                                    }       

                            }
                            $no_test_country++;
                    }   

```