Thanks, Davoud and Savage.
I've been confused about this red dot clicking in Photoshop since
upgrading recently to Creative Cloud from version 5.1. In previous
versions of Photoshop (before tabs) clicking on the red dot closed only
the file whose red dot one clicked on.
Also, this new behaviour of Photoshop is inconsistent with clicking on
the red dot in the top, left corner of browser windows; in browsers,
doing so closes only the file whose red dot one clicks on. So that,
too has confused me since upgrading to Creative Cloud.
Also, this new behaviour is inconsistent within the Creative Cloud
programs; in Photoshop and Indesign, clicking the red circle closes all
open, saved files -- but in Dreamweaver, it closes only the top file,
so that also has confused me and should be made consistent by Adobe.
Anyway, thantks, Davoud and Savage, for the tips. I'll remember now to
click on the tiny, black "x" to the left of the tab title to close an
open, saved file.
Tom Evans