I'm wondering how to capture variables posted back from an external website.

Whenever I try, I get an error like:

[Notice] Undefined index: customer_fname
GET /register/approved

Line 25 in /var/www/vhosts/domain.com/subdomains/subsite/httpdocs/mysite/code/RegistrationPage.php
Source

16 		parent::init();
17  	}
18 
19 	static $public_actions = array (
20 		'doRegister'
21 	);
22 	
23 	public function approved() {
24 		if(isset($_POST)) {
25 			$con = "Full Name: ".$_POST["customer_fname"]." ".$_POST["customer_lname"]."<br />";
26 			$con .= "E-mail Address: ".$_POST["email"]."<br />";
27 			$con .= "Username &amp; Password: ".$_POST["username"]." / ".$_POST["password"]."<br />";
28 			$con .= "Subscription Amount: ".$_POST["recurringFormattedPrice"];
29 		} else
30 			$con = "oops!";
31 

Am I doing it right? :p

is there no one to answer this?