Newbie question - value list displaying data

[jon-e-orange]

Sorry if I have posted this in the wrong place.

I am relatively new to FM - I have made our office job book and timesheets into a FM DB that has worked so great my boss want's me to extend it to include other items such as billing.

All my Tables are linked by "job number" as the Primary Key.

I have a table called "time list" this has the fields: Job no, date, work done, who, task, time.

Task is a value list with (at the moment) 3 options: Design, Artwork and Admin.

( I display this in our job book using a portal and I have a total time filed there. All works fine.)

I need on another table to be able to show how much time there is for each task.

Can I do this with a calculation?

what is the best way of doing this?

Cheers

Jon-e-orange