The return page you refer to contains the following.

Undefined subroutine &main::start_html called at D:\Web\Forex Ballot\g
+roundhog.pl line 10.
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In order to use the functions of a module you have to use the module. So previous advice from moritz to use DBI (and the appropriate DBD) applies but you also need to use the CGI module, and as you are using it in a non-OO fashion, you need to use it in the standard form, and you may need to debug your html so you should print it in a way you can read. Thus:

use CGI::Pretty qw(:standard);
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Read through the book again looking at all the words ;)