Q: How do I show previews of two different parts of my document, in one window? I am running TeXShop 2.47 on a G5 PPC Mac with OS 10.5.8.
The last time I was working in LaTeX I accidentally did something which caused my preview window to split into two subwindows, with one section of the document on top and another on the bottom. I don't know what I did to make this happen but it was very useful, allowing me to search through what I had written in one subwindow while displaying what I was working on in the other.
The next time I opened the program it was back to the usual single preview window with no subdivisions, and I cannot figure out how to get the two subwindows. I expected to find what I wanted by selecting Preview >> Display Format >> Double Page, but this only changes how one page transitions to another when scrolling.
How do I do this?

A: Okay, there is a button in the upper right corner of the preview window that looks like two little rectangles with lines in them, one on top of the other. Pressing that toggles between the display I described and ordinary one.
