How can I limit ads to certain URL's?

[=MGN=RedEagle]

I want to make it so that the ads that certain ads don't show on certain pages. Say I put 1 ad in the sidebar but I don't want that ad to show on the index page. How do I do that?

 

[=MGN=RedEagle]

Oops! Wrong forum, can a mod delete this?

 

[Samet Chan]

Ad = Advertisement?

Home page or forum, sidebar? Screenshot maybe?