Hi James, it's just a web page, so assuming there isn't an overlay you need to click off, you can just close the tab or navigate to a new page using the address bar, a bookmark, etc.

Maybe I didn't understand your question?

No closing the tab closes the page. the next time I start Firefox this page keeps starting and I can't find away to eliminate it. My default page also starts which is OK. But every time this ad page starts also. I know there is a place that I use to go to remove this situation. Thank You