affiliate like tracking pixel

We want a affiliate like tracking pixel. So when a person clicks on a banner it goes to server A and places a cookie. THen it is redirected to a url on another server (B). The user goes over that server and maybe even leaves that server. But at a moment it arrives at a certaind page. THere we can place a pixel or a javascript. We what that that pixel or script on server B calls a scrip on server A so the value of that pixel is saved in a database on server A. On server A we can use php. On server B only html and javascript.