php oo help

I am VERY new to OO. I am trying to learn it because I went to get more into OO.

Here is a program I started. The 1st class is executed with no problems but it does not look like the 2nd class is being executed. I plan to divide my work into multiple classes.

index.php

<?php
session_start();
include "settings.php";

require_once('classes/login.class.php');
require_once('classes/general.class.php');

        /*
        Login and check login system
        Version 1.0
        7/12/2013
        Robert Saylor
        */

        $check_login = new Login($linkID);
        // check if login data was posted
        if (isset($_POST['section']) == "login") {
                $check_login->login($_POST['uuname'],$_POST['uupass']);
        }


        // set varibles for login
        $uuname = '';
        $uupass = '';
        $token = '';
        if(isset($_SESSION['uuname'])) { $uuname = $_SESSION['uuname']; }
        if(isset($_SESSION['uupass'])) { $uupass = $_SESSION['uupass']; }
        if(isset($_SESSION['token'])) { $token = $_SESSION['token']; }
        // done varibles

        $check_login->check_login($uuname,$uupass,$token);

        /* END LOGIN SYSTEM */

        /* Main Program */
        $general = new General($linkID);
        if (isset($_GET['section']) == "destinations") {
                $list_general->destinations();
        }


        foreach ($_GET as $key=>$value) {
                print "K $key V $value<br>\n";
        }

?>

login.class.php

<?php

class Login {

        function __construct($linkID){}

        public function login($user,$pass) {
                global $linkID;
                $sql = "SELECT * FROM `users` WHERE `uuname` = '$user' AND `uupass` = '$pass'";
                $result = $linkID->query($sql) or die($linkID->error.__LINE__);
                $row = $result->fetch_assoc();
                if($result->num_rows > 0) {
                        // get a new token
                        $new_token = $this->token();
                        $sql2 = "UPDATE `users` SET `token` = '$new_token' WHERE `id` = '$row[id]'";
                        $result2 = $linkID->query($sql2) or die($linkID->error.__LINE__);

                        // Set session data
                        $_SESSION['uuname'] = $row['uuname'];
                        $_SESSION['uupass'] = $row['uupass'];
                        $_SESSION['token'] = $new_token;
                }
        }

        public function token() {
                $length = 40;
                $string = "";
                while ($length > 0) {
                        $string .= dechex(mt_rand(0,15));
                        $length -= 1;
                }
                return $string;
        }

        public function check_login($user,$pass,$token) {
                global $linkID;
                $sql = "SELECT * FROM `users` WHERE `uuname` = '$user' AND `token` = '$token' LIMIT 1";
                $result = $linkID->query($sql) or die($linkID->error.__LINE__);
                $row = $result->fetch_assoc();
                if($result->num_rows > 0) {
                        if (($row['uuname'] == $user) and ($row['token'] == $token)) {
                                // ok logged in
                                print "You are logged in!<br>\n";

                        }
                } else {
                        /*
                        passes the user to the function login_form if they are not logged in.
                        */
                        $error = "You are NOT logged in!";
                        $this->login_form($error);
                }
        }

        public function login_form($error) {
                if(isset($error)){
                        print "$error";
                }
                print "
                <form action=\"index.php\" method=\"post\">
                <input type=\"hidden\" name=\"section\" value=\"login\">
                <table border=0 width=50%>
                <tr><td>Username:</td><td><input type=\"text\" name=\"uuname\" size=40></td></tr>
                <tr><td>Password:</td><td><input type=\"password\" name=\"uupass\" size=40></td></tr>
                <tr><td>&nbsp;</td><td><input type=\"submit\" value=\"Login\"></td></tr>
                </table>
                </form>
                ";

        }
}
?>

general.class.php

<?php

class General {

        function __construct($linkID){}

        public function destinations() {

                global $linkID;

                $sql = "
                SELECT
                `reserve`.`boats`.`fleet` AS 'fleet2',
                `af_df`.`destinations`.*

                FROM
                `af_df`.`destinations`, `reserve`.`boats`

                WHERE
                `af_df`.`destinations`.`boatID` = `reserve`.`boats`.`boatID`

                ORDER BY `reserve`.`boats`.`fleet` ASC, `af_df`.`destinations`.`name` ASC
                ";

                print "<h2><u>Current Destination(s)</u></h2><br>\n";
                print "<table border=0 width=80% cellpadding=3 cellspacing=0>
                <tr><td><b>Destination</b></td><td><b>Title</b></td><td><b>Active</b></td><td>&nbsp;</td></tr>\n";

                $result = $linkID->query($sql) or die($linkID->error.__LINE__);
                if($result->num_rows > 0) {
                        while($row = $result->fetch_assoc()) {
                                print "<tr $bgcolor1><td>$row[name]</td><td>$row[title]</td><td>$row[active]</td><td>";
                                print "<a href=\"index.php?section=dest&part=add&update=1&id=$row[id]\">Edit</a> |
                                <a href=\"index.php?section=dest_del&id=$row[id]>\" onclick=\"return confirm('You are about to delete destination $row[name] from the database. Click OK to continue.')\">Delete</a>
                                </td></tr>";
                        }
                } else {
                        print "<tr><td colspan=4><center><font color=blue>Sorry, there are no destinations defined. Please add a destination.</font></center></td></tr>\n";
                }
               print "</table>";
        }



}
?>