These are a few practical examples, with the XML that generates them and PHP that processes them. Also, for security concerns this does not display the PHP variables, however it will email you or display a message.

This is to show how to use this in an email form. It uses a regular expression to make sure that it is a valid email address, then sends the message to that email address. Source XML

Email Address
Message

This is a demonstration of a very simple login form. User name is "user" and the password is "password". Source XML

User Name
Password

This is a demonstration of a very simple registration form. Source XML

Email Address
User Name
Password
Password Confirm
	Subscription 1
	Subscription 2
	Subscription 3
Gender	malefemale
I have read and accepted the terms and conditions
	Yes
	no