I need to create a table with three columns - Start Date, End Date and number of Days in between. where, if one of the values in either of the columns is changed the other one updates by itself.

For example: Start Date End Date No of Days
1/1/2014 1/10/2014 10
1/10/2014 1/15/2014 5
and so on...

If I change the end date 1/15/2014 then the no of days should update itself or If I change the no of days then, the dates should get updated depending on the change.


Please Help.