Thread structure showing

I just touched my finger on something by accident (iPad) and now the thread outlines are all showing. Tried to find anything that looks like whatever button that might have been, was unsuccessful. How do I get rid of it?

Oh, and btw, things are good in our house. Our son just turned 16, a landmark birthday. More tomorrow.

Looks like there is a button on the "reply topic" row that says "FLAT" -- try that. If you select FLAT then the THREADED option appears -- seems like a toggle button.

Thanks! That's all I needed.