xymalf on "Program not running"

require_once 'Tag.php';

I have put above code in my main plugin code yet it does not seem to call the program?

// Your secret Api Key. Required for hashing and auth.
var $secret_access_key = "Umt84XrzvtfimG2FHjhDJFgxj7mlLEksb";
// Your public Api Key
var $access_key = "AKIAIQ2ZQ6JWDC5";
// Your associate ID
var $associate_tag = "xymalfsentert-20";
// Serveradress of the webservice
var $server = "";
// Service Name
var $service = "";
// The type of Operation
var $operation = "";
// States which representation should be used.
var $responseGroup = "";
// Some Services need a version string, stored here.
var $version = "";
// Last query URL used
var $queryUrl = "";
// If true, the signature auth will be used.
var $use_signatureAuth = false;
// If true, the associate Id will be used.
var $use_associateTag = true;

what values should i put between the "" for a simple product search on Amazon API?