code: private void doMoveSelectionInList(int moveBy)
  	{
  		PlayListEntry [] selected = playList.getSelectedEntries();
  		if (selected==null || selected.length == 0)
  		{
  			playList.setSelectedElement(0);
  			doMakeIndexVisible(0);
  		}
  		else
  		{
  			int index = selected[0].getIndexInPlaylist();
  			index += moveBy;
  			if (index<0) index = 0;
  			else
  			if (index>=playList.size()) index = playList.size() - 1;
  			playList.setSelectedElement(index);
  			if (moveBy <0) index-=PLUS_LINES_VISABLE; else index+=PLUS_LINES_VISABLE;
  			doMakeIndexVisible(index);
  		}
  	}
docs: Moves the selection (cursor)
  @param moveBy
  @since 15.12.2011