freezing data from updating in forms

Hello,
How to prevent the updating or requering of query
values in a MS Access Form using a command button?

My program refreshes the data whenever there is a change
in one of the formulae. I want to keep track of the older
vaules. Henceforth, I want that the form not to updat any
value according to the new formulae unless it is asked to
do so, by a control, say a command button.

Thank you in advance for any valuble suggestion.

With Regards,
Swaminathan