foreach $key (sort {$a <=> $b} $query->param()) {
   # rearrange:
   next if ($query->param($key) =~ /^\s*$/);
   next if ($key !~ /^filetoupload_(\d+)$/);

   # next condition is a subset of the previous condition
   # i.e., $key cannot be empty AND match filetoupload_\d+
   #next if ($key =~ /^\s*$/);

   $Number = $1;

   # only one matching group:  (        )   
   if ($query->param($key) =~ /([^\/\\]+)$/) {
      $Filename = $1;
      $Filename =~ s/^\.+//;

      # hence, no $2
      #$pxuser = $2;
      #$pxuser =~ s/^\.+//;

      $files{$Number} = $Filename;
      $File_Handle = $query->param($key);

   if (!$ALLOW_INDEX && $Filename =~ /^index/i) {
       print header;