Using a button to change alpha

How can I make a button so that when the mouse rolls over it, the alpha of a different symbol changes?

Is this possible?

Any help would be greatly appreciated.

Yes it is possible. And here is the easiest way.

On the clip you want the alpha to change add a keyframe into frames 1 and 2 (this is if you want it visible first then fade out, if you don’t want it visible, just leave the first frame blank).

Add a stop() action to frame 1. Create a new keyframe at the end of your animation. In the grey area between frames 2 and the last right click and choose “Create Motion Tween”. Do the same for the last frame.

Now click on the object in the last frame and open up the properties panel (CTRL+F3). There should be a drop down box set to “None” as default, choose “Alpha” as the setting and put this to 0 (if you want the object to fade in, keep the last frames object set at None, while the second frames object is set at Alpha 0).

Now add a stop() action on the last Frame.

On your button use this actionscript…’

on(rollOver){
_root.fadeClip.gotoAndPlay(2);
}

fadeClip = the instance name of your movie clip with the fade animation.

And of course for roll out effect just reverse the fade process and use gotoAndPlay(frame#) at the frame that starts the rollout fade animation.