Automatically assigning values to hidden SUBFORM fields based on MAIN FORM check box

[Spidey3721]

I have a subform in datasheet format where I am doing a lot of data entry
for job budget numbers. I would like the main form to have either a check
box or some option buttons that will determine the value of certain hidden
fields as new records are created. For example

If my main form has an option button for ACTUAL (cost type) / BUDGET (cost
type).

I want the user to be able to set the option to BUDGET and then use the
subform (in datasheet view) to enter costs and cost data - I do not want a
visible COST TYPE field in my subform, but want it to be filled in as BUDGET
automatically/by default...

 

[jag]

I have a subform in datasheet format where I am doing a lot of data entry
for job budget numbers. I would like the main form to have either a check
box or some option buttons that will determine the value of certain hidden
fields as new records are created. For example

If my main form has an option button for ACTUAL (cost type) / BUDGET (cost
type).

I want the user to be able to set the option to BUDGET and then use the
subform (in datasheet view) to enter costs and cost data - I do not want a
visible COST TYPE field in my subform, but want it to be filled in as BUDGET
automatically/by default...