public boolean checkLogin(String username, String password){
        boolean is_Correct = false;
        try {
            URL url = new URL(this.url);
            HttpURLConnection conn = (HttpURLConnection)url.openConnection();
            conn.setRequestMethod("POST");
            conn.setDoOutput(true);
            conn.setDoInput(true);
            conn.setUseCaches(false);
            BufferedWriter output = new BufferedWriter(new OutputStreamWriter(conn.getOutputStream(),"UTF-8"));
            output.write("func=Login");
            output.write("username="+username);
            output.write("password="+password);
            BufferedReader input = new BufferedReader(new InputStreamReader(conn.getInputStream(),"UTF-8"));
            String result = input.readLine();
            output.flush();
            output.close();
        }catch(Exception e){
            e.printStackTrace();
        }
        return is_Correct;
    }