I bet it's this :

print $query->popup_menu(-name=>'directory',
                             -values=>\@dir,
                             -labels=>\@dir=>\@users);
[download]

The last bit of this, -labels=>\@dir=>\@users is probably malformed (This looks like CGI, but it could be tk, I dunno. I don't work with tk at all.)
Cutting and pasting does not always save time *g*