Let's look a the timeline again. If you'll remember, we set the frame rate for this document to 12 frames per second; that means that twelve of the blocks in the timeline will make up one second of animation. I want my circle to move over one second, so I'm going to click on the twelfth block; the timeline is marked in increments of five, so just count two after the "10" marker. If you right-click on the 12th frame, you'll see two keyframe options: "Insert Keyframe" and "Insert Blank Keyframe". You'll want to click on "Insert Keyframe"; this automatically copies everything on the previous keyframe (including our circle) to the new keyframe.
After clicking "Insert Keyframe", you can see that now the 12th frame is grayed out and marked with a dot, just like the first; the space in between them is also grayed, with the 11th frame marked by a small white square. This indicates that there is no motion or "tween" placed on the frames in between; Flash has automatically placed a hold on these frames so that they continuously fill with a repeat of the key frame.
So now, technically, we have a one-second animation--only the animation doesn't actually visibly move. In the next step we'll move things around a little, and start to really get our animation off the ground.
