Recursion... Sort of...

Is there a way to tell if a function has been called that has resulted
in a call to the same function?

We have an in-house CRM app that has a function that draws a tabbed
panel on a screen... BUT if there are sub-sub-tabbed panels we want to
invert the tab colors and panel colors...

So...

DrawSubTab($Set) - Black on White
   Content
   DrawSubTab($Set) - White on Black
      Content
      DrawSubTab($Set) - Black on White
         Content
      DrawSubTab($Set) - Black on White
         Content
         Etc...

I suppose I could rewrite EVERY call to the function with a recursion
count like DrawSubTab($Set,$DepthCount+1) but that would be a MASSIVE
commit... whereas if the function can determine itself... All that
said I can't think of a good way to do it without a bastardized global
variable that track "how deep" we are and there is something that
bothers me about that approach... Unless that really is the easiest
way.

Thanks in advance!

Matt