...
&middle_of_page($dbh, $dbuser, $dbpass);     # main content, DBI results, etc.
...

sub middle_of_page {
  my ($dbh, $dbuser, $dbpass) = @_;
  # ...
  $dbh  = DBI->connect('DBI:whatever', $dbuser, $dbpass, {RaiseError => 1});
  # prepare, execute and print query results
  # wrapped in HTML elements
}