protected void removeUpdate(DefaultDocumentEvent chng){
  super.removeUpdate(chng);
  buffer.remove(chng.getOffset(),chng.getLength(),chng);
}

protected void removeUpdate ( DefaultDocumentEvent chng ) { super . removeUpdate ( chng ) ; buffer . remove ( chng . getOffset ( ) , chng . getLength ( ) , chng ) ; }
updates document structure as a result of text removal .
