Calculating a Total from a SubDataset in Access 2000

Hi All,

I have a Subform as a dataset, which which hold ‘activity’ data, especially:

[Total]
which is calculated from:
=[Hours]*[HourlyRate]

On the primary form ‘Stage’, i want to calculate [Total_Cost] which is the total of all Activities appling to that stage.

Currently the subdatasets link correctly, but i cannot get the values to carry up to ‘Stage’.

Any help would be great.