# look to see if the windows don't overlap 
        if ($test lt $window[0]) {return 0;}
        # look to see if the windows don't overlap
        elsif ($test2 lt $probe[0]) {return 0;}

##</code><code>##

sub range_overlap {
  my ($start1, $end1, $start2, $end2);
  return ($end1 >= $start2 || $start1 <= $end2) &&
         ($end2 >= $start1 || $start2 <= $end1);
}