If the data entered by a client was incorrect or was simply missing, the server would have to send all the data back to the client and request that the form be resubmitted with correct information.This was really a lengthy process which used to put a lot of burden on the server.Form validation is the process of checking that a form has been filled in correctly before it is processed.
Let's build a simple form with a validation script.
Microsoft® Office Front Page® 2003 allows you to create some custom validation within the form feature.
(For more information on how to create form validation using the Front Page form feature, see About creating forms in Front Page 2003.) However, if the form validation provided in Front Page does not suit your needs or the site on which you are working is hosted on a server that does not have Front Page Server Extensions from Microsoft installed, you may need to create custom form validation.
Shows you how to write a script that ensures your form is filled in correctly before it's sent to your server.
Great for "required fields" such as email addresses!