Transparent area

This is probably a dumb question but I'm new to this and can't find the answer anywhere.

How do I set an area to be transparent in ActionScript 3.0?

At the moment I'm creating a subtitles area to sit over the player and it has the following code:

? subtitlesArea.x = player.x;
?subtitlesArea.y = player.y;
?subtitlesArea.width = player.width;
?subtitlesArea.height = player.height;

Is it just a case of adding ssth like this?!

?subtitlesArea.transparency = true;

Transparent area

You can set the alpha property to 0 or you can set the visible property to false.

subtitlesArea.alpha = 0; // 1 for full visibility

subtitlesArea.visible = false;?// true for full visibility