public void login(String userName, String password) {
        try {
          String parameters = "user=" + URLEncoder.encode(userName, "UTF-8") + "&password=" + URLEncoder.encode(password, "UTF-8") + "&version=" + 13;
          String result = Util.excutePost("https://login.minecraft.net/", parameters);
          if (result == null) {
        	  LauncherFrame.notificationLabel.setText("Can't connect to minecraft.net");
            return;
          }
          if (!result.contains(":")) {
            if (result.trim().equals("Bad login")) {
            	LauncherFrame.notificationLabel.setText("Login failed");
            } else if (result.trim().equals("Old version")) {
              LauncherFrame.notificationLabel.setText("Outdated launcher");
            } else {
            	LauncherFrame.notificationLabel.setText(result);
            }

            return;
          }
          String[] values = result.split(":");
          GameLauncher.username = values[2].trim();
	      GameLauncher.sessionId = values[3].trim();
          Downloader.startThread();
        } catch (Exception e) {
  	      e.printStackTrace();
  	      System.out.println(e.toString());
  	      LauncherFrame.notificationLabel.setText("Connessione assente!");
  	    }
        }