>I agree, except that there are some mission critical apps where this is not an option. In some apps, the record stays open and edited until no longer needed and is updated while something is occurring. In that case, the value must be saved when focus leaves the control and that value must be immediately visible to all other users. When that is case, I choose to use the LOSTFOCUS() when possible instead of the valid.

It's actually the same - validate on save. It's just the save happening much more often.