Field-level validation (as opposed to form-level validation) has
to do with the verification of data entered into an individual field. Typically
(but not always), field-level validation is performed without regard to the contents
of other fields on the form. The appropriate times to perform field-level validation
are:
-
As the user enters individual keystrokes into the field (Keystroke events
as described in previous sections).
-
When the user attempts to leave the field—since we presume that the
user considers the field entry to be complete (Validate event).
-
When the field changes for any reason (Change event).
Following topics are covered under this section:
