use CGI;

$query = new CGI;
@letters=("a", "b", "c");
%labels=('1=>a',
         '2=>b',
         '3=>c');

print     $query->header(-title=>'some letters & labels'),
          $query->start_html('Welcome to letters'),
          $query->h1('Welcome letters'),
          $query->h3("Please select the what you would like to"),
          $query->p,
          $query->checkbox_group(-name=>'avletters',
                                 -values=>\@letters,
                                 -labels=>\%labels),
          $query->p,
          ...