How do I make Fields Required in Dreamweaver?

I have been working on this for a two days now and have no idea what to do. First I learned out to creat a form and I am using a php script to send the form.

This is the link to the HTML form:

http://www.webznmore.net/Custom%20WeddingGuestBookOrder.html

And here is the php script to send this:

http://www.webznmore.net/customweddingguestbookorder.php

And I keep getting this error message and it will not send. It only started this when I set the validation to Required in Dreamweaver Behaviors.

The other form still works fine but I have not set any of the fields to required yet. Here is the link to the one that is still working:

http://www.webznmore.net/OrderCandyBuffet.html

What am I doing wrong? I even took off all the validations on the first one to just try and get it working again and it just will not work at all anymore.

Desperate cry for help.