I use Firefox on my Mac Mini. For some unknown reason, when my Firefox home page has changed from opening as a full screen view to a small box in the upper right part of my screen. Then I have to change it to the full screen view. I would like to find out how to get it changed back to always opening with a full screen view, please. Also, why is there no customer service phone number posted? Some of us prefer phone support, rather than typing questions and hoping someone knows the answer and takes time to respond.