Someone

    $doc .= "<access authSystem=\"knb\" order=\"denyFirst\">\n";
    $doc .= "<allow>\n";
    $doc .= "<principal>$username</principal>\n";
    $doc .= "<permission>all</permission>\n";
    $doc .= "</allow>\n";

    if($moderators eq ''){
    if($FORM::username ne ''){
            $doc .= "<allow>\n";
            $doc .= "<principal>uid=$FORM::username,o=$FORM::organization,dc=ecoinformatics,dc=org</principal>\n";
            $doc .= "<permission>all</permission>\n";
            $doc .= "</allow>\n";
    } else {
        my $session = CGI::Session->load();
            if ( !$session->is_empty ) {
                my $username = $session->param("username");
                $doc .= "<allow>\n";
                $doc .= "<principal>$username</principal>\n";
                $doc .= "<permission>all</permission>\n";
                $doc .= "</allow>\n";
        }
    }
    } else {
        foreach(split(":",$moderators)){
            $doc .= "<allow>\n";
            $doc .= "<principal>".$_."</principal>\n";
            $doc .= "<permission>all</permission>\n";
            $doc .= "</allow>\n";
        }

    if($FORM::username ne ''){
                $doc .= "<allow>\n";
                $doc .= "<principal>uid=$FORM::username,o=$FORM::organization,dc=ecoinformatics,dc=org</principal>\n";
                $doc .= "<permission>read</permission>\n";
                $doc .= "<permission>write</permission>\n";
                $doc .= "</allow>\n";
        } else {
                my $session = CGI::Session->load();
                if ( !$session->is_empty ) {
                        my $username = $session->param("username");
                    $doc .= "<allow>\n";
                        $doc .= "<principal>$username</principal>\n";
                    $doc .= "<permission>read</permission>\n";
                    $doc .= "<permission>write</permission>\n";
                    $doc .= "</allow>\n";
                }
        }
    }

    if($publicReadable eq "true"){
        $doc .= "<allow>\n";
        $doc .= "<principal>public</principal>\n";
        $doc .= "<permission>read</permission>\n";
        $doc .= "</allow>\n";
    }
    $doc .= "</access>\n";