void hideBorder(){
  Insets insets=getInsets();
  setBorder(BorderFactory.createEmptyBorder(insets.top,insets.left,insets.bottom,insets.right));
}

void hideBorder ( ) { Insets insets = getInsets ( ) ; setBorder ( BorderFactory . createEmptyBorder ( insets . top , insets . left , insets . bottom , insets . right ) ) ; }
hide the special border of the title bar .
