use CGI::Session;

my $s;

sub new_session {
    $s = CGI::Session->new() or croak CGI::Session->errstr(); 
}

sub check_perm {

    my $req_perm = shift;

    if ($s->param('_perm') < $req_perm) { 
        print $s->header(), 'sorry, no permussion';
        exit();
    }
}