When does a background process complete?

[V. Mark Lehky]

I have written a recursive function (one that calls itself).  In an attempt
to speed it up, I have made the call to itself in the background, using the
"&" symbol.
Here is my problem: I then have a script which calls this function the
first time.  Subsequent commands in this script need to have everything
this function does completed.  How can I detect, from my script, when all
the processes from this function have completed?
I can post the actual code, if it will help.  Here is almost pseudo-code to
hopefully descripbe what I am looking for:

function my_function
{
   if stop condition false
      my_function &
   else
      return
}
# begin script
my_function
# now I need to find out if all the background tasks have completed
continue with script ...

TIA, Mark L.