[Access 2007] Calculate hours

[ultra5219]

hello :)

i have problem doing calculations in access for timetable. well im trying to calculate based on my timetable table where total hours of:

-no class

-with class

- total overall hours which is (total no class +total with class)

i did try using datediff function , but still not successful

can anyone tell me or teach me steps by steps how to do based on my database.

Thanks again..

schedule hrs calculate.zip