Restore the last date the user selected.

I have a form that adds log records. When the form is first opened up I want the date field to default to TODAYS DATE, But if the user changes that date and saves a record I want the date field to default to the LAST DATE they selected.

I seem to only be able to do it one way or the other. I can write the code if I knew the form was the first time ONLOAD or after a record was added and its the second time ONLOAD. If that makes sense.

Thanks

Andy