flash actionscript: I want to have a movie clip appear when the mouse rolls over another mc and disappear when it rolls out.

you cn use timeline effects(gotoandplay("showMC2") within an onClipEvent()
handler->
****************************************(do a search within the ActionScript
dictionary on this function, or online)

,->where showMC2 is a frame on the main timeline where mc2 is placed..

you can use event handlers (onClipEvent(rollOver)) to attachMovie("mc2")

The first option is probably more suitable

So if I have 30 mc's and each one controls a different mc, i would need 30 frames.

Or I could have a dynamic text box and as I roll over different movie clips
the variable for the text box changes value.

I guess I need to know how to do a rollover on a movie clip. I can't seem to
get anything to happen.

I'm trying :

myMovieClip.onRollOver = myFunction();

Then have myFunction do what I want. Doesn't seem to work tho. Anybody know
how to do this simple thing?

myMovieClip.onRollOver = function()
{
...code...
}

OR

place this code on your mc
on(rollover)
{
.....code....
}

****One of these is the syntax you need if your using ActionScript 1.
Everything becomes much cleaner if you have the option of using AS2.

In regards to your visiblility idea, you can set the _visible property of a mc
to true or false. This option would also work.