#!C:/perl/bin/perl.exe

# scriptname: index.pl

BEGIN {
   my $development = 0;
   if ($development) {
      use CGI::Carp qw(fatalsToBrowser);
   }
   else {
      use CGI::Carp qw(fatalsToBrowser set_message carpout);

      open(LOG, ">>datadir/trap_error") or
         die("Unable to open mycgi_log: $!\n");
      carpout(LOG);

      sub handle_errors {
         print "<h1>Script Error</h1>";
         print qq~<p>An error occurred while processing your request. This error has been noted and appropriate action will be taken to rectify it.</p>~;
      }
      set_message(\&handle_errors);
   }
}

use Mymodule1;
use Mymodule2;

my $query = get_param('node') || 'start';

# Rest of code in the main script...