Ordinarily I hate coming here with newbie code questions but nobody can find the error with this code. Maybe you guys can :-)

<?php
defined('SYSPATH') or die('No direct script access.');

/**
 * to interact with photos
 *
 * @author Max Padraig Wolfgang Bucknell-Leahy
 */
class Model_Photos
{
    private $apiKey = '12664498208a1380fe49fb1b5a238ef0';
    private $secret = '03d43dee65a34513';
    private $perms  = 'read';
    private $sigString = 'test';
    private $apiSig = md5($_sigString);
    private $authArray = array('api_key' => $apiKey,
    'perms'  => $perms,
    'api_sig' => $apiSig);
    private $authArrayImploded = implode('&', $authArray);

    private $authLink = 'http://www.flickr.com/services/auth/?' . $authArrayImploded;

    public function get_photos($number = 5)
    {
     if(file_exists(APPPATH . 'cache/main_cache.xml')
     {
      echo $authLink;
     } else {
      echo 'not so good';

      /**


      */
     }
    }
}

$class = new Model_Photos;

$class->get_photos;

the error is:

Parse error: syntax error, unexpected '(', expecting ',' or ';' in /home/p14s9nnd/public_html/testing.php on line 15

Thank you in advance and sorry

Regards, Max