[flexcoders] Accordion question - height minus header space

[lanekelly5]

I'd like to size the TileLists inside each accordion panel properly.  
If I have 4 panels (and thus 4 header buttons for navigation), how can 
I calculate the available space for a panel?  I assume this would be 
the specified height of the accordion minus the height of a header * 
numChildren.  Anyone know if there's a property that already has this 
info or how to calculate the hight of a header (assuming that they are 
all the same size)?