use strict;
use warnings;
use CGI;
my $content_type = 'text/html';
my $web_page = "<h1>hello world</h1>";
my $CGI_obj = $CGI_obj->new;
# either:
print $CGI_obj->header($content_type);
# or (uncomment 1 line below and comment 1 line above)
# print "Content-type: text/html\n\n";
print $CGI_obj->start_html;
print $web_page;
print $CGI_obj->end_html;