MACROMEDIA STUDIO 8-EXPLORING STUDIO 8 Manual page 65

When you're working with a large number of frames that can't all be
displayed in the Timeline at once, you can move the playhead along the
Timeline to easily display a specific frame.
To go to a frame:
Click the frame's location in the Timeline header, or drag the playhead
to the desired position.
To center the Timeline on the current frame:
Click the Center Frame button at the bottom of the Timeline.
Changing the display of frames in the Timeline
You can change the size of frames in the Timeline, and add color to
sequences of frames to highlight them. You can also include thumbnail
previews of frame content in the Timeline. These thumbnails are useful as
an overview of the animation, but they require extra screen space.
Frame View pop-up menu
Short and Normal frame view options
Frame View button
Flash basics 65