my $Folder;
my $Readme;

##</code><code>##

my %folder_options=('170'=>'winvista',
 '173'=>'winvista64', 
 '119'=>'winvxp', 
 '210'=>'winxp64', 
 '541'=>'windows*7 graphics', 
 '525'=>'winvista64');
my $Folder=$folder_options{$operatingsystem};

##</code><code>##

my $Folder;
my $Readme;
SWITCH:
{
   ($operatingsystem eq '170') and do {
          $Folder='winvista';
          $Readme='readme_winvista.txt';
          last SWITCH;
    } 
   ($operatingsystem eq '173') and do {
          $Folder='winvista64';
          $Readme='readme_winvista64.txt';
          last SWITCH;
    } 
}

##</code><code>##

   use Switch;
   my $Folder;
   my $Readme;
    switch ($operatingsystem) {
        case '170'          { $Folder='winvista';
                              $Readme='readme_winvista.txt';
                            }
        case '173'          { $Folder='winvista64';
                              $Readme='readme_winvista64.txt';
                            }
    }