# note that these two vars go together to a certain extent.
my $magic="===&01";
my $escape="%=&";

sub unpack_hash {
  my ($str)=shift;
  my %hash;

  if (substr($str,0,6) eq $magic) {
    substr($str,0,6)='';
    %hash=map { map { 
                      s/%(\d)/substr($escape,$1,1)/ge;
                      $_
                   } split /=/,$_ 
                 } split /&/,$str;
    
  } else {
    # old getVars() support...
  }
}

sub pack_hash {
  my $hash=shift;
  return $magic.join("&",map { 
    join "=",map { 
         (my $v=$_)=~s/([$escape])/'%'.index($escape,$1)/ge 
         $v
    } $_ => $hash{$_}     
  } sort keys %$hash);
}