test.pl:

#!/usr/bin/perl

use strict;
use CGI;
use CGI::Carp "fatalsToBrowser";
use Database;


print "Content-type: text/html\r\n\r\n";
print "Hello World";
test();

Database.pm:

#!/usr/bin/perl

package Database;

sub test()
{
  print "Hello World again\n";
};

1;