Gossamer Forum: Products: Links 2.0: Customization: modification in review.cgi

In review.cgi, users are not allow to post 2 reviews regarding the same link. The limitations are set by the same IP address along with the same link (as seen in the code below).

In Reply To:

next unless ($values[$db_linkid] eq $in{$db_cols[$db_linkid]} && $values[$db_ip] eq $ENV{'REMOTE_ADDR'});
&site_html_review_failure ("Sorry, you've already reviewed this resource once recently.") and return;

The problem comes when 2 different users are submitting reviews using the same computer on the link. I would like to have the email address incorporated as an additional limitation requirement. I tried the following by it doesn't work:

In Reply To:

next unless ($values[$db_linkid] eq $in{$db_cols[$db_linkid]} && $values[$db_ip] eq $ENV{'REMOTE_ADDR'} && $values[$db_contact_email] eq $in{$db_cols[$db_contact_email]});
&site_html_review_failure ("Sorry, you've already reviewed this resource once recently.") and return;

I appreciate any help,
Adrian