Transparent area

OK, I think this is a simple question but I can't seem to find an answer anywhere!

I'm overlaying my Flash Player with a 'subtitlesArea' where subtitles will appear. Dumb question, but how in Actionscript 3.0 do you set the area to be transparent?

My code for setting the area is:

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

Is it sth as simple as adding:

??subtitlesArea.transparency = 1;