else
up_btn = new JButton( "Up" );
up_btn.setMargin( btn_insets );
up_btn.setToolTipText( "Scroll Upward by half a screen" );
// up_btn.setPreferredSize( btn_dim );
up_btn.addActionListener( new ActionVportUp( y_scrollbar ) );
up_btn.setMnemonic( KeyEvent.VK_UP );
super.add( up_btn );
icon_URL = getURL( Const.IMG_PATH + "Down24.gif" );
if ( icon_URL != null )