Read the perldocs on the CGI.pm module by doing

   perldoc CGI
[download]

at a command prompt. In there you'll find the pieces for this:

    use CGI;         # load CGI routines
    $q = new CGI;    # create new CGI object
    @values = $q->param('foo');
[download]

Now, translated to your SELECT box it might look something like this:

    use CGI;         # load CGI routines
    $q = new CGI;    # create new CGI object
    @select_values = $q->param('sel');
[download]

HTH.