Flash Animation 24: Flash for Web Design: Creating a Thumbnail Gallery

We want to put all of this content on a single frame, as a single "page". First create a new layer for your thumbnails; then click on the single frame that you've designated to contain your gallery. Right-click, and select Insert Keyframe. (If you began adding content without first inserting a keyframe, the content would automatically create a keyframe on the first frame and stretch for the full duration of the animation. You would then have to edit your timeline subsequently to remove content from all but that one frame; it's easier to just add the empty keyframe first so that any content added there is confined.)