It can be frustrating to look over feedback that's been submitted via a form on your Web page, only to notice that your visitor failed to provide a name, email address, or some other piece of critical information. That's why, depending on the type of form you create, you might want to make certain information mandatory.
For instance, a form used for subscribing to an email newsletter isn't much use if the would-be reader doesn't type in an email address for receiving it. Likewise, if you need a shipping address to deliver a brochure or product, you'll want to be sure that the visitor included his address on the form.
Unfortunately there's a built-in limitation to this Dreamweaver behavior: you can only validate text fields. In other words, you can't check to see whether someone clicked a particular checkbox or made a selection from a pull-down menu. Nor can you see if she chose a file to upload or clicked a radio button. (For some more advanced solutions, see the box ...