help with form data synchronising required

[Norman Fritag]

Hi there

I have a form wish is used to doubt check data been entered before it is
updated to the main table.
I structured the form into 3 tabs of which the first on represents the total
amount entered by date.
the second tab represents the total amounts by date and Area
the 3rd tab represents the amounts entered by date, by area, Product (detail
section)

Now I like the person checking if the entries are correct to start at the
first tab.
When staff enters the curser into any date field of the first tab (data
source is a subform), I like to synchronise / link alien the data and
contents of tab 2,3 to reflect only data entries of the date selected ( in
first tab).

The same is achieve by making the data of the first tab the source of the
main form, then use a drop down listbox to find a record in the form. If I
have the data in tab 2,3 (as subform linked on date = date), then data will
change after the afterupdate event of the dropdown listbox is completed, to
link on the date selected.

Amy ideas?
Which event I would could use? or what structure the form requires?

Kind regards

Norman