PHP Delete file in all directories

Delete file in all directories

<?
davai("software","ws_ftp");

function davai($dir,$string) {
  $handle = opendir($dir);
  while ($file = readdir($handle)) {
    if ($file != "." && $file != "..") {
      if (is_file("$dir/$file")) {
        if (eregi("$string", "$file")) {
          $rez = eregi_replace("$string", "<B>$string</B>", $file);
          unlink("$dir/$file");
          echo "Deleted $dir/$file<BR>";
        }
      }
      else { davai("$dir/$file",$string); }
    }
  }
}
?>