我正在使用登录功能，但是遇到了我无法弄清的错误。

这是我的模型登录类：

class Login {

    private $username;
    private $password;
    private $cxn;       //database object

    function __construct($username,$password)
    {
        //set data
        $this->setData($username, $password);
        //connect DB
        $this->connectToDB();
        // get Data 
    }

    function setData($username, $password)
    {
        $this->username = $username;
        $this->password = $password;
    }

    private function connectToDB()
    {
        include 'Database.php';
        $connect = '../include/connect.php';
        $this->cxn = new database($connect);  
    }

    function getData()
    {
        $query = "SELECT * FROM anvandare WHERE anvandarnamn = '$this->username' AND losenord ='$this->'password'";
        $sql = mysql_query($query);

        if(mysql_num_rows($sql)>0)
        {
            return true;
        }
        else
        {
            throw new Exception("Användarnamnet eller Lösenordet är fel. Försök igen.");
        } 
    }

    function close() 
    {
        $this->cxn->close(); //Here is the error it says "Method 'close' not found in class
    }
}

最后一个函数给出错误“ 在类中找不到方法’close’ ”，“ 在主题类中找不到引用的方法。 ”

这是我的数据库类：

class Database {

    private $host;
    private $user;
    private $password;                  
    private $database;

   function __construct($filename)
   {       
       if(is_file($filename)) include $filename;
       else throw new exception("Error!");

       $this->host=$host;
       $this->user=$user;
       $this->password=$password;
       $this->database=$database;

       $this->connect();
    }

    private function connect()
    {
        //Connect to the server
        if(!mysql_connect($this->host, $this->user, $this->password))
        throw new exception("Error, not connected to the server.");

        //Select the database
        if(!mysql_select_db($this->database))
        throw new exception("Error, no database selected");             
    }

    function close()
    {
        mysql_close();
    }
}

路径是正确的，事实并非如此。可能是什么错误？