$q = CGI->new();
    %form = $q->Vars;
...
    $file = $form{photo};
    $fh = upload('photo') || error ($q,"Cannot upload file $file");
    $info = uploadInfo($q->param('photo')) || error ($q,"Could not get information about $file!");

    unless ($errors)
    {
        $type = $info->{'Content-Type'};
        unless ($type =~ m,^image/(jpeg|gif|png)$,)
        {
            error ($q, "File type '$type' is not permitted");
        }
...