Actually, Daniel's code will WORK, but it's not very pretty! It's true that
the check boxes on all the records will be enabled/disabled depending on the
condition of whichever record has focus. If RecordA's condition dictates that
the checkbox be enabled, all checkboxes will be enabled. But if you try to
click on the checkbox in RecordB, whose condition dictates that the checkbox
be disabled, you won't be able to, because RecordB now has focus, and all the
checkboxes are now disabled! Also, if you try to click on the checkbox of a
record where the checkbox should be enabled, but the previous record with
focus had the checkbox disabled, you'll have to click twice to get the box
checked! The first click gives focus to the record and the second click
actually checks the box. As I said, it will function, but it's not pretty!
The only real way to deal with formatting records in a continuous form is
thru Conditional Formatting, and unfortunately, Conditional Formatting is not
supported for Checkboxes.