Sure. Set the brush duration to infinite. And by all means do read the help. This is basic stuff that can be easily answered by reading the relevant chapters.
Thanks so much! For the Duration options, however, I only see Constant, Write On, Single Frame, and Custom. Am I looking at the wrong panel?? Also, I was trying to take a look at the guide adobe has about Paint, (After Effects Help | Paint tools: Brush, Clone Stamp,and Eraser) but didn't see anything about infinite duration. Am I looking in the wrong spot?? Thanks so much for your help!!!!!!
Your custom setting is for 12 frames. If your composition is 400 frames long set the duration to 400 or more. Simple as that.
All of this stuff is in the help files.
Thank you very much. Custom works a bit, But the first frame is not erasing while the frames following are erased the way I want them to be. I should probably also add that I want to put more than one photo have have them all erased in one particular section for the whole duration of the video.