Add a Keyframe
Flash CS4 Tutorial
How to Add Keyframe to Flash Timeline
Keyframes are used to define an object at a specific point in time. For instance, you could set a keyframe at frame one where your object is transparent. A second keyframe is added at frame ten where the object is opaque.
A tween is then applied between the keyframes and the object fades from transparent to opaque in ten frames. In this example we use a Classic Tween. You could also use a Motion Tween. For more information, see topics, Classic Tween and Motion Tween.
Add a rectangular object to the workspace with the Rectangle tool (r key).
With the rectangle selected, convert the object to a movie symbol by pressing F8 (Modify > Convert to Symbol). Name the symbol in the dialog box.
The layer with the rectangle has one keyframe by default at frame one. Click frame 10 and press F6 (Insert > Timeline > Keyframe). A new keyframe is added that contains the same content as frame one.
Click the first keyframe, then click the rectangle to access its options.
In the Properties panel, open the Color Effect section. choose Alpha from the Style pull down menu. Set the alpha value to 0.
Click between the frames (i.e., frame 5) and choose Insert > Classic Tween. You can also Ctrl-click (PC-Right-click) the middle frame area and choose Create Classic Tween from the menu.
Test your movie (Control > Test Movie) (Cmd/Return (PC-Ctrl/Enter) to view the animation.