@Override
 public boolean onFragmentCreate() {
     super.onFragmentCreate();
     NotificationCenter.Instance.addObserver(this, MessagesController.mediaDidLoaded);
     NotificationCenter.Instance.addObserver(this, MessagesController.messagesDeleted);
     NotificationCenter.Instance.addObserver(this, MessagesController.didReceivedNewMessages);
     NotificationCenter.Instance.addObserver(this, MessagesController.messageReceivedByServer);
     dialog_id = getArguments().getLong("dialog_id", 0);
     loading = true;
     MessagesController.Instance.loadMedia(dialog_id, 0, 50, 0, true, classGuid);
     return true;
 }
 private void saveName() {
   MessagesController.Instance.changeChatTitle(chat_id, firstNameField.getText().toString());
 }