Free hosting biz, random ad

I run a free hosting biz, and I want to get something back from it. I need a very simple code done, that will pick from a pool of ads in a specific folder, and make them a popup. In this folder, I will make an HTML page for each ad. Then the user will put a short code (javascript?) on their page (short as in 1-2 lines) - then when someone goes to their site, a popunder will happen, presenting a random HTML ad in the folder. The popunder window must be a specific size, like 400x600 or something. I need this done ASAP and i'm on a very tight budget! I don't think it will take long at all. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Installation package that will install the software (in ready-to-run condition) on the platform(s) specified in this bid request. 3) Complete ownership and distribution copyrights to all work purchased. ## Platform UNIX