adding keywords in URL for google adwords

I'd like to have keywords in my urls for google adwords. if google adwords has not indexed a page, it is not sure what ad to serve. if it has keywords in the url, it serves up better ads. I ofund that simply adding a parameter served up better ads, such as "adkw=Music".

I'd like to see my forum name as a keyword. when you click on the forum, such as music, it should show the normal showforum.php then adkw=Music as an ad keyword.