The HTML 5 specification includes a number of features for form validation. Form elements have a number of new attributes like required, min, max, pattern and new data types that allow the browser to either present a UI that prevents invalid data entry or validate the entered data and prevent the form being submitted if it is incorrect. The LANSA framework includes some enhancements that add support for RDMLX data types to the validation, add some extra functionality and address some inconsistencies in browser implementation.
Also see
9.2.2 Displaying Validation Errors
9.2.3 Controlling When Validation Occurs
