Looking for a solution: different banners for different pages

Dear friends,

First of all: HAPPY NEW YEAR!

After this, I would like you to help me :-P: I am using my WordPress as a CMS. I am looking for a widget plugin that allows me to display different ads to some different pages. I mean, for example, I have page1, page2 and I have banner-group1 and banner-group2. I want to show the banner-group in the page1 and the banner-group2 in page2 (in the sidebar, of course :-)). I am looking for a plugin that helps me on this!!!

Thnaks a lot for your help!