$rth=$dbh->prepare("select max(id) from zen order by id") 
        or die("Can't connect: ", $dbh->errstr);
    $rth->execute;
    $id=$rth->fetchrow_array;
    $selid=int(rand($id)+1);
    $tth=$dbh->prepare("select koan from zen where id=$selid") 
        or die("Can't connect: ",$dbh->errstr);

    $tth->execute;
    $koan = $tth->fetchrow_array;

##</code><code>##


    $tth=$dbh->prepare("select koan from zen order by rand() limit 1") 
        or die("Can't connect: ",$dbh->errstr);

    $tth->execute;
    $koan = $tth->fetchrow_array;