@machines=("a", "b", "c");
use CGI qw(:standard);
 $q = new CGI;
 #$q->use_named_parameters(1);

 print $q->header(-title=>'SI',
                  -author=>'me'),
       $q->p,
       $q->start_html('Welcome'),
       $q->p,
       $q->h1('Welcome'),
       $q->h3('Which machine would you like to Analyize?'),
       $q->popup_menu(-name=>'machines',
                            -values=>\@machines),
       $q->p,
       $q->submit;
       $machine=$q->param('machines');
       $q->end_html;

 if ($q->params) {
      <do some stuff>
 }