Draw a shape in the usual way.
Modify, Movie,then Match Contents to adjust size to just the objects size. You don't want any background to show.
Select the entire item with the arrow tool.
Click on Insert, Convert to Symbol.
Name the button.
Select Button for the Behavior.
Click okay.
Double click on the button. You should see the four states instead of the usual timeline.
Create the Over state...Click on the Over frame, select Insert, Keyframe.
Modify the Over state any way you wish.
Create the Down state...Click on the Down frame, select Insert, Keyframe.
Modify the Down state any way you wish. you might want to select it and move it slightly down and to the right.
Click on Window, then Actions.
Click on Basic Actions, then double-click on Get URL.
You should have a box that allows you to enter a URL such as http://www.yahoo.com.
Enter something...
Save the file.
Adding a Rollover Sound
Click on the Over keyframe.
Click on Window, Common Libraries, Sounds.
Drag a sound onto the stage.
Click on Control, Test Movie.
Invisible Buttons
Create a button by clicking on Insert, New Symbol, Name it and select button, then click okay.
Do not add keyframes in Up, Over, or Down timeline boxes.
Add a keyframe in the Hit box.
Draw a circle over the + sign on the stage.
Click on Scene One.
Open the library and drag an instance out onto the stage. It will look different butu that is okay. The pale blue color is normal for an invisible button.
Test the button. You should see that it functions as a button but is not visible.
Add the URL or other action in the usual manner.
This button is useful in situations where you want to have links on a large graphic. It is similar to mapping images in Dreamweaver.