This tutorial will show you how to create a Java Script-enabled form that checks whether a user has filled in the form correctly before it's sent to the server. First we'll explain why form validation is a useful thing, and then build up a simple example form, explaining things as we go along.
At the end, there's a little exercise to keep you busy too!
The form will include one text field called "Your Name", and a button.
Our validation script will ensure that the user enters their name before the form is sent to the server. Try pressing the Send Details button without filling anything in the "Your Name" field.
So if you select the second item in the drop down, a text field associated with that selection appears.