Verifying a required element

 
if (strlen($_POST['email']) == 0) {
   $errors[] = "You must enter an e-mail address.";
}

1.	Basic PHP form processing
2.	Changing a value in $_POST
3.	if else to check posted variables
4.	Superglobals vs. Globals
5.	Testing a required field
6.	Set Cookie Data

Verifying a required element : _POST « Form « PHP