if ($ENV{'REQUEST_METHOD'} eq "GET") {
  for (split(/\&/, $ENV{'QUERY_STRING'}) {
    if (($name, $value) = /(.*)=(.*)/) { ## Normal
      $value =~ ## Unescape $value here
    }
    else { ## Abnormal, no "equal"!
      $name =$_; $value=0;
    }
    $name =~ ## unescape $name here
}