求个一个smarty写的登记登录页面

========================db.php=====================
class DB {
    private $host;
    private $db_name;
    private $user_name;
    private $password;
    private $conn;
    
    public function __construct($host, $user_name, $password, $db_name) {
        $this->host = $host;
        $this->user_name = $user_name;
        $this->password = $password;
        $this->db_name = $db_name;
        $this->connect();
    }
    public function connect() {
        $this->conn = mysql_connect($this->host, $this->user_name, $this->password) or die("数据库连接失败!");
        mysql_select_db($this->db_name);
        mysql_query("SET CHARACTER SET utf8");
    }
    public function getObj($sql) {
        $rs = mysql_query($sql, $this->conn) or die (mysql_error());
        $arr = array();
        while ($row = mysql_fetch_array($rs)) {
            if (!empty($row))
                $arr[] = $row;
        }
        return $arr;
    }
    public function add_data($table, $fields = array(), $values = array()) {
        $sql = "insert into " .  $table . "(" ;
        for($i = 0; $i < count($fields); $i++) {
            if ($i < count($fields) - 1)
                $sql .= $fields[$i] . ',';
            else
                $sql .= $fields[$i] . ")";
        }
        $sql .= " values (";
        for($i = 0; $i < count($values); $i++) {
            if ($i < count($values) - 1)
                $sql .= "'" . $values[$i] . "'" . ',';
            else
                $sql .= "'" . $values[$i] . "')";
        }
        mysql_query($sql, $this->conn) or die (mysql_error());
        $insert_id = mysql_insert_id($this->conn) or die (mysql_error());
        return $insert_id;
    }
    public function close() {
        mysql_close($this->conn);
    }
   
}
$db = new DB('localhost', 'root', '', 'test');
?>
==========================User类=====================================
require './Mysql/db.php';
?>

class User {
    private $user_name;
    private $password;
    private $table;
    function __construct($table, $user_name, $password) {
        $this->user_name = $user_name;
        $this->password = $password;
        $this->table = $table;
    }
    public function add_user() {
        global $db;
        $user_data = array($this->user_name, $this->password);
        return $db->add_data($this->table, array('user_name', 'password'), $user_data);
    }
    public function get_user($user_name) {
        global $db;
        $sql = "select * from $this->table where user_name = '" . $user_name . " '";
        return $db->getObj($sql);
    }
    
}
?>

===================user.php================================
session_start();
header("Content-type: text/html; charset=utf-8"); 
require 'User.class.php';
require './Smarty-2.6.26/libs/Smarty.class.php';
$smarty = new Smarty;
$smarty->compile_check = true;
$smarty->debugging = false;

if (isset($_REQUEST['act']) && $_REQUEST['act'] == 'register') {
    $user_name = $_REQUEST['user'];
    $password = $_REQUEST['password'];
    $user = new User('user', $user_name, $password);
    $user_arr = $user->get_user($user_name);
    if (empty($user_arr)) {
        $user->add_user();
        echo "用户注册成功!" . "
";
    } else {
        echo "用户已经存在!" . "
";
    }
} elseif (isset($_REQUEST['act']) && $_REQUEST['act'] == 'login') {
    $user_name = $_REQUEST['user'];
    $password = $_REQUEST['password'];
    $user = new User('user', $user_name, $password);
    $user_arr = $user->get_user($user_name);
    if (empty($user_arr)) {        
        echo "用户不存在!" . "
";
    } else {
        if ($user_arr[0]['user_name'] == $user_name && $user_arr[0]['password'] == $password) {
            echo "登录成功!"; 
            /***
             * 然后就是记录session,跳转到登录成功的页面
             * 把用户名使用smarty常用的assign变量方法，在注册成功的页面取出来，
             */
        }
    }
} elseif (isset($_REQUEST['act']) && $_REQUEST['act'] == 'login_page'){
    $smarty->display('login.html');
} elseif (isset($_REQUEST['act']) && $_REQUEST['act'] == 'register_page'){
    $smarty->display('register.html');
} else {
    $smarty->display('register.html');
}

?>


==============register.html==============


    
        
        
    
    
        
    


==============login.html=========================