compare between range

["lameck kassana" <chelaskk@xxxxxxxxx>]

hey i have database called timetable in mysql the fields are

 starttime                    endtime
     19                              21
     15                              16

suppose i want to insert want to insert new starttime 17 to endtime 21 from
php script .How will  try to compare my range with my database range .


   thanks for advance.

laskkkassana