Select All/Clear All

I'm stumped and need help.

I have a page with several checkboxes that all have an initial state of selected.

When the page loads, an action group calculates a series of numbers based on whether the associated checkboxes are selected. (On load, all the numbers are included in the calculation.)

The user can choose to clear checkboxes to exclude numbers from the calculation. And then reselect those checkboxes to recalculate the results.

All of this works beautifully.

Now I need to add a Select/Clear All check box - and this is my problem. This should clear or select all of the other checkboxes on the page and then rerun the calculation.

I have a variable associated with the Select All checkbox. The state of this changes appropriately when I click it.

I have variables associated with the other checkboxes on the page, and the state of the variables appears to change (at least according to what I see in Debug mode)

However, the checkboxes do not clear (or become selected), nor do they run the action group to recalculate.

Does anyone have any suggestions?

Any help would be greatly appreciated!