Compositing: Can I have multiple masks in one composite? To have one mask on a comp it will follow this compositing node flow: 

Render layerA of Mask (Alpha) -connects to- Mix (Factor)

Render layerB of BG (Image) -connects to-   Mix (Image1)

Render layerC of MaskBG (Image) -connects to- Mix (Image2)

From this one Mix node is created one complete image, but using just one masked area.  

I need to create an image with multiple mask areas.  How do I do it?  

The problem I run into is that I don't know what node I would need to combine multiple masks onto the one background image.  

Please help.  :)
Stop looking!  I've worked it out.  :D

The answer is: Once you create one image using an alpha mask you then use this as your background layer for the NEXT alpha mask, and so on, and so on.  

It felt like a puzzle in a computer game that I just solved. Now I'm on the next level.  

Sweet!