Instead of using event  code to validate each field as it is edited, why not wait
until the user indicates (by clicking an 'OK' or 'Add record' button or
whatever) that the data  should be appended to the list? Then validate every
field before appending the data. I do this with a single (lengthy) validation
function that notifies the user of the first error encountered and ultimately
returns TRUE if no errors were found  or FALSE if any errors were found. Also, if
the user quits the session (closes the form, etc.) before attempting to commit
the record, no effort is spent validating data that won't be used.

Hope this helps,

Your validation  should be done when the user clicks the Save or OK button -
whatever actually causes the information to be used, and presumably also
causes the form  to close.

You can do validation on field changes earlier if you like - although I
prefer not to. (I'd rather let the user do a visual scan and fix problems,
prior to hitting OK.)