sub count_occurrences{
  my($part, $whole, $cs)=@_;

  # $part -- the text you're searching for
  # $whole - the string within you're searching
  # $cs   -- case sensitive? 1=yes, 0=no  (may be omitted for non cs search)

  my($count)=0; 
  my($null)="\0";
  if($cs==1){
   while($whole=~/$part/s){
    $count++;
    $whole=~s/$part/$null/;
   }
  }else{
   while($whole=~/$part/is){
    $count++;
    $whole=~s/$part/$null/i;
   }
  }
  return $count;
}