to calculate distance of lat and long from database table and also difference of 1st and 2nd latlongs

Figure : 1,
 Database table

Vehicleid   Latitude    Longitude   datetime
1   16.43924553090  79.92235564210  2012-12-19 16:00:00.000
1   16.43517902890  79.92466106060  2012-12-19 16:02:00.000
1   16.43111252690  79.92498125760  2012-12-19 16:04:00.000
1   16.42797459620  79.92517337580  2012-12-19 16:06:00.000
2   14.68807134570  79.50083987840  2012-12-19 17:12:00.000
2   14.68514259410  79.51420230760  2012-12-19 17:14:00.000
3   18.56690251930  82.50047999880  2012-12-19 18:22:00.000
3   18.56884750210  82.50426359800  2012-12-19 18:24:00.000

Based on above figure1 (database table), how to calculate distance between starting and ending points by using c# .net  and also at the same time insert the starting( lat& long) and ending (lat & long) as well as strating time, ending time, distance values in another table like below table


Vehicleid   Starting(lat & long)    Ending (lat  & long)    Distance(in kms)    Strat time  End time
1   16.43924553090, 79.92235564210  16.43517902890,
79.92466106060  ?   2012-12-19 16:00:00.000 2012-12-19 16:02:00.000
1   16.43517902890,
79.92466106060  16.43111252690,
79.92498125760  ?   2012-12-19 16:02:00.000 2012-12-19 16:04:00.000
1   16.43111252690,
79.92498125760  16.42797459620,
79.92517337580  ?   2012-12-19 16:04:00.000 2012-12-19 16:06:00.000