$server_user="xxx";
$server_pass="xxx";
$host_server="mysql.wz.cz:3306";
$name_db="xxx";
$spojeni=MYSQL_connect($host_server,$server_user,$server_pass);
$tab_prihlaseni="prihlaseni";
$atr_login ="login";
$atr_heslo ="heslo";


if (isset($_POST["auth_login"])) {
    if (mysql_result(mysql_query("SELECT COUNT(*) FROM $tab_prihlaseni WHERE $atr_login = '" . mysql_real_escape_string($_POST["auth_login"]) . "' AND $atr_heslo = '" . md5($_POST["auth_heslo"]) . "'"), 0)) {
        session_regenerate_id(); // ochrana před Session Fixation
        $_SESSION["$atr_login"] = true;
    }
}
if (!isset($_SESSION["logged"])) {
    if (isset($_POST["auth_login"])) {
        echo "<p>Neplatné přihlašovací údaje.</p>\n";
    }
    echo "<form action='index-login.php' method='post'>\n";
    echo "<p>Login: <input name='auth_login' maxlength='30' /></p>\n";
    echo "<p>Heslo: <input type='password' name='auth_heslo' /></p>\n";
    echo "<p><input type='submit' value='Přihlásit' /></p>\n";
    echo "</form>\n";
    exit;
}