common::stringToBoolean PHP Method

    function stringToBoolean($value)
    {
        switch (strtoupper($value)) {
            case 'TRUE':
                return TRUE;
            case 'FALSE':
                return FALSE;
            default:
                return NULL;
        }
    }

 function authenticate($login, $password, $remember = FALSE, $forward = TRUE, $origin = NULL)
 {
     $common = new common();
     // Get all the administrators from the administrators.xml file.
     $administrators = simplexml_load_file($_SERVER['DOCUMENT_ROOT'] . "/data/administrators.xml") or die("Error: Cannot create administrators object");
     foreach ($administrators as $administrator) {
         // If or when we get to a matching login compare the supplied password to the one stored inadministrators.xml.
         if ($administrator->login == $login) {
             if (password_verify($password, $administrator->password)) {
                 // Set the session variable Authenticated to TRUE and assign the variable Login the supplied login.
                 $_SESSION['authenticated'] = TRUE;
                 $_SESSION['login'] = $login;
                 $_SESSION['firstLogin'] = $common->stringToBoolean($administrator->firstLogin);
                 // If the user wishes to be remembered set a cookie containg the authenticated and login variables.
                 if ($remember) {
                     setcookie("authenticated", TRUE, time() + 10 * 365 * 24 * 60 * 60);
                     setcookie("login", $login, time() + 10 * 365 * 24 * 60 * 60);
                     setcookie("firstLogin", $common->stringToBoolean($administrator->firstLogin), time() + 10 * 365 * 24 * 60 * 60);
                 }
                 // Forward the user if the $forward variable is set to TRUE.
                 if ($forward) {
                     if (isset($origin)) {
                         // Redirect the authenticated visitor to their original destination.
                         header("Location: " . urldecode($origin));
                     } else {
                         // Redirect the user to the administration homepage.
                         header("Location: index.php");
                     }
                 }
                 return TRUE;
             }
         }
     }
     // If things got this far authentication failed.
     return FALSE;
 }