A general point of order: don't print a list of strings, print just one multi-line string:

    print header(),
          start_html('INDEX'),    
          q{<p>This is the index page!<br><br>
          <a href="index.pl">index</a><br>
          <a href="index.pl?page=page2">page2</a><br>
          <a href="index.pl?page=page3">page3</a><br>},
          end_html();
[download]

We're not in BASIC any more.