@Override
  public void onClick(View v) {
    switch (v.getId()) {
      case R.id.sem1:
        student.setSubject(1);
        break;

      case R.id.sem2:
        student.setSubject(2);
        break;

      case R.id.sem3:
        student.setSubject(3);
        break;

      case R.id.sem4:
        student.setSubject(4);
        break;

      case R.id.sem5:
        student.setSubject(5);
        break;

      case R.id.sem6:
        student.setSubject(6);
        break;
    }

    Fragment fragment;
    FragmentTransaction ft = getFragmentManager().beginTransaction();
    fragment = new notes_unit_select();
    ft.replace(R.id.content_main, fragment);
    ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
    ft.addToBackStack(null);
    ft.commit();
  }
  @Nullable
  @Override
  public View onCreateView(
      LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.notes_subject_select, container, false);

    sub1 = (Button) view.findViewById(R.id.sub1);
    sub2 = (Button) view.findViewById(R.id.sub2);
    sub3 = (Button) view.findViewById(R.id.sub3);
    sub4 = (Button) view.findViewById(R.id.sub4);
    sub5 = (Button) view.findViewById(R.id.sub5);
    sub6 = (Button) view.findViewById(R.id.sub6);

    sub1.setOnClickListener(this);
    sub2.setOnClickListener(this);
    sub3.setOnClickListener(this);
    sub4.setOnClickListener(this);
    sub5.setOnClickListener(this);
    sub6.setOnClickListener(this);

    if (teacher.getBranch().equals("CS")) {

      if (student.getSemester() == 1) {
        sub1.setText("Mathematics 1");
        sub2.setText("Physics");
        sub3.setText("electrical");
        sub4.setText("elements of mechanical engg");
        sub5.setText("civil");
        sub6.setText("cip");
      } else if (student.getSemester() == 2) {
        sub1.setText("Mathematics 2");
        sub2.setText("chemistry");
        sub3.setText("caed");
        sub4.setText("electronics");
        sub5.setText("ccp");
        sub6.setText("evs");
      } else if (student.getSemester() == 3) {

      } else if (student.getSemester() == 4) {

      } else if (student.getSemester() == 5) {
        sub1.setText("Software engineering");
        sub2.setText("system Software");
        sub3.setText("operating system");
        sub4.setText("dbms");
        sub5.setText("computer networks 1");
        sub6.setText("flat");
      } else if (student.getSemester() == 6) {

      } else if (student.getSemester() == 7) {

      } else if (student.getSemester() == 8) {

      }
    } else if (teacher.getBranch().equals("IS")) {

      if (student.getSemester() == 1) {
        sub1.setText("Mathematics 1");
        sub2.setText("Physics");
        sub3.setText("electrical");
        sub4.setText("elements of mechanical engg");
        sub5.setText("civil");
        sub6.setText("cip");
      } else if (student.getSemester() == 2) {
        sub1.setText("Mathematics 2");
        sub2.setText("chemistry");
        sub3.setText("caed");
        sub4.setText("electronics");
        sub5.setText("ccp");
        sub6.setText("evs");
      } else if (student.getSemester() == 3) {

      } else if (student.getSemester() == 4) {

      } else if (student.getSemester() == 5) {
        sub1.setText("Software engineering");
        sub2.setText("system Software");
        sub3.setText("operating system");
        sub4.setText("dbms");
        sub5.setText("computer networks 1");
        sub6.setText("flat");
      } else if (student.getSemester() == 6) {

      } else if (student.getSemester() == 7) {

      } else if (student.getSemester() == 8) {

      }
    } else if (teacher.getBranch().equals("EC")) {

      if (student.getSemester() == 1) {
        sub1.setText("Mathematics 1");
        sub2.setText("Physics");
        sub3.setText("electrical");
        sub4.setText("elements of mechanical engg");
        sub5.setText("civil");
        sub6.setText("cip");
      } else if (student.getSemester() == 2) {
        sub1.setText("Mathematics 2");
        sub2.setText("chemistry");
        sub3.setText("caed");
        sub4.setText("electronics");
        sub5.setText("ccp");
        sub6.setText("evs");
      } else if (student.getSemester() == 3) {

      } else if (student.getSemester() == 4) {

      } else if (student.getSemester() == 5) {

      } else if (student.getSemester() == 6) {

      } else if (student.getSemester() == 7) {

      } else if (student.getSemester() == 8) {

      }
    } else if (teacher.getBranch().equals("EE")) {

      if (student.getSemester() == 1) {
        sub1.setText("Mathematics 1");
        sub2.setText("Physics");
        sub3.setText("electrical");
        sub4.setText("elements of mechanical engg");
        sub5.setText("civil");
        sub6.setText("cip");
      } else if (student.getSemester() == 2) {
        sub1.setText("Mathematics 2");
        sub2.setText("chemistry");
        sub3.setText("caed");
        sub4.setText("electronics");
        sub5.setText("ccp");
        sub6.setText("evs");
      } else if (student.getSemester() == 3) {

      } else if (student.getSemester() == 4) {

      } else if (student.getSemester() == 5) {

      } else if (student.getSemester() == 6) {

      } else if (student.getSemester() == 7) {

      } else if (student.getSemester() == 8) {

      }
    } else if (teacher.getBranch().equals("IT")) {

      if (student.getSemester() == 1) {
        sub1.setText("Mathematics 1");
        sub2.setText("Physics");
        sub3.setText("electrical");
        sub4.setText("elements of mechanical engg");
        sub5.setText("civil");
        sub6.setText("cip");
      } else if (student.getSemester() == 2) {
        sub1.setText("Mathematics 2");
        sub2.setText("chemistry");
        sub3.setText("caed");
        sub4.setText("electronics");
        sub5.setText("ccp");
        sub6.setText("evs");
      } else if (student.getSemester() == 3) {

      } else if (student.getSemester() == 4) {

      } else if (student.getSemester() == 5) {

      } else if (student.getSemester() == 6) {

      } else if (student.getSemester() == 7) {

      } else if (student.getSemester() == 8) {

      }
    } else if (teacher.getBranch().equals("ME")) {

      if (student.getSemester() == 1) {
        sub1.setText("Mathematics 1");
        sub2.setText("Physics");
        sub3.setText("electrical");
        sub4.setText("elements of mechanical engg");
        sub5.setText("civil");
        sub6.setText("cip");
      } else if (student.getSemester() == 2) {
        sub1.setText("Mathematics 2");
        sub2.setText("chemistry");
        sub3.setText("caed");
        sub4.setText("electronics");
        sub5.setText("ccp");
        sub6.setText("evs");
      } else if (student.getSemester() == 3) {

      } else if (student.getSemester() == 4) {

      } else if (student.getSemester() == 5) {

      } else if (student.getSemester() == 6) {

      } else if (student.getSemester() == 7) {

      } else if (student.getSemester() == 8) {

      }
    } else if (teacher.getBranch().equals("CIV")) {

      if (student.getSemester() == 1) {
        sub1.setText("Mathematics 1");
        sub2.setText("Physics");
        sub3.setText("electrical");
        sub4.setText("elements of mechanical engg");
        sub5.setText("civil");
        sub6.setText("cip");
      } else if (student.getSemester() == 2) {
        sub1.setText("Mathematics 2");
        sub2.setText("chemistry");
        sub3.setText("caed");
        sub4.setText("electronics");
        sub5.setText("ccp");
        sub6.setText("evs");
      } else if (student.getSemester() == 3) {

      } else if (student.getSemester() == 4) {

      } else if (student.getSemester() == 5) {

      } else if (student.getSemester() == 6) {

      } else if (student.getSemester() == 7) {

      } else if (student.getSemester() == 8) {

      }
    }

    return view;
  }