private void backupLastUndo() {
		if (undoVec.size()>0) {
			File f = new File(dataFilePath+File.separator+((String)undoVec.get(undoVec.size()-1)));
			if (f!=null && f.exists()) {
				copy(f, new File(f.getParentFile().getParentFile(),"backup.xml"));
			}
		}
	}