To insert 30 frames in your movie with the use of mouse:
Click frame 30 in the layer 1 on the timeline - then press F5
Now you need to find that the element you want to tween.( It can be any element you like ) .
Then choose Libraries > Graphics in the menu.
Then Library - Grapics opens.
Then Find Bird and with the mouse, drag it into the canvas.
Then use the scale tool in the toolbox, to resize the bird as you like.
(If your version of Flash does not contain "bird", then just use any other symbol).
Now enter a keyframe in the frame 30. To do this, first click
in frame 30 in layer one on the timeline. After that press F6.
Then double click the keyframe in frame 1.
Then a frame Properties Box pops up.
Then choose "Tweening", and in the Tweening drop-down menu choose "Motion".
Right click on the Layer 1.
Then a pop-up menu appears.
Then choose Add Motion Guide.
Flash now inserts a new layer on the top of layer 1,
with the Motion Guide icon to the left of the layer's name.
This new layer is called as motion guide layer.
Motion guide layer is used to draw lines that you want an animated symbol to follow.
Click on the Motion Guide Layer to make sure that it is the active layer.(Click on the layer name, where it says "Guide: Layer 1").
Then choose pencil in the toolbox. (Or press P on the keyboard)
Make sure that pencil mode is set to "Smooth".
With the pencil draw the line where you want the bird to fly along.
For example, draw a wave like path through which the bird will fly.
Now adjust the frame pointer so that it points to frame 1.
Make sure that the Snap button is activated (or choose
View > Snap in the menu, to activate snapping).
With the mouse,you can place the bird so that its center is at the beginning of your motion guide.(The center is indicated by a small + when selected).
A black circle appear when the bird is attached to the motion guide.
It can sometimes be hard to get the symbol to snap to guide. Eventually it will be though :o)
Try zooming out or in if you just can't get the bird to snap to the guide.
Release the mouse button as soon as the bird is snapped to the guide.
Now adjust the frame pointer in such a way that it points at frame 30. Repeat the process by placing the bird at the end of the motion guide