IN THIS CHAPTER
Validating data as it is being entered
Validating data immediately prior to submission
Organizing complex data-validation tasks
You have two opportunities to perform data-entry validation in a form: as the user enters data into a form and just before the form is submitted. I recommend you take advantage of both of these opportunities.
The most convenient time to catch an error is immediately after the user makes it—especially for a long form that requests a wide variety of information. You can make the user's experience less frustrating if you catch an entry mistake just after the user enters the information: his or her attention is already focused on the nature ...