Login.class

<?php
    class Login
    {
        static public $username;
        static public $password;

        public function __construct($username, $password)
        {
            $this -> username = $username;
            $this -> password = $password;
            require 'mysql.inc';
        }

        public function Check_Inputs()
        {
            $SQL   = "Select * FROM mitglieder WHERE name = '" . $this -> username . "'";
            $Query = mysql_query($SQL);
            $row   = mysql_fetch_assoc($Query);
            if(md5($this -> password) === $row['passwort'])
            {
                return true;
            }else{

                return false;
            }

        }

        public function Login()
        {
            session_start();
            $_SESSION['xxPmmalAe'] = true;
            $_SESSION['Name']      = $this -> username;

        }

    }
?>

Login.php

<?php
    class Login
    {
        static public $username;
        static public $password;

        public function __construct($username, $password)
        {
            $this -> username = $username;
            $this -> password = $password;
            require 'mysql.inc';
        }

        public function Check_Inputs()
        {
            $SQL   = "Select * FROM mitglieder WHERE name = '" . $this -> username . "'";
            $Query = mysql_query($SQL);
            $row   = mysql_fetch_assoc($Query);
            if(md5($this -> password) === $row['passwort'])
            {
                return true;
            }else{

                return false;
            }

        }

        public function Login()
        {
            session_start();
            $_SESSION['xxPmmalAe'] = true;
            $_SESSION['Name']      = $this -> username;

        }

    }
?>

mysql.inc

<?php

mysql_connect('localhost', 'root', '');
mysql_select_db('skriptdb');

?>