my GetLink = 'one&reaction=two';
query string xxx.cgi?action=' + GetLink;    

##</code><code>##

my $query = new CGI;
my $action = lc ($query->param('action'));

.......

elsif ($action eq "one"){
  my ($string1, $string1 ) = @_;
  my ($string2, $string2 ) = @_;
  warn("string2 = '$string2'");

##</code><code>##


elsif ($action eq "one"){
  my $query = CGI->new();
  my $string2 = $query->param('reaction');
  warn("string2 = '$string2'");