unless ( param ) {
    print login_form();
    exit;
}

sub login_form {
    return
        header,
        start_html(
            -title => 'Login',
            -style => {
                -src => "../../xml_final/db.css"}),
            center(
                h1('Please login'),
                start_form,
                        'username:', textfield( -name => 'username'),
                        'password:', password_field( -name => 'password'),
                        submit('send'),
                        reset,
                end_form,
                a({ -href => 'newuser.pl'}, 'New User?') ),
        end_html;
}