private String getFileContent(){
		if(fileName!=null){
			BufferedReader reader = null;
			String content = null;
			try{
				//for Chinese, using the encoding UTF-8
				reader = new BufferedReader(new InputStreamReader(new FileInputStream(fileName),"UTF-8"));
				String temp = null;
				while((temp = reader.readLine())!=null){
					content+=temp;
				}
				reader.close();
				return content;
			} catch(IOException ex){
				logger.log(Level.SEVERE,"Read the XML file",ex);
			}
		}
		return null;
	}