Vivian, that's definitely a good trick. I think, though, that by "locking layers," what's being referred to is the ability to move all the layers together as if they were one. Thus, if you want everything to go to the left a smidge, you don't have to go into every last blessed layer to change its pan settings. Just lock the layers, grab them, and shove them en masse. Boy, would that ever save a lot of time!