public void RadioButtonClicked(View view) {
   boolean checked = ((RadioButton) view).isChecked();
   switch(view.getId()) {
      case R.id.radio_button1:
         if (checked)
         db.insert("","","","","","","Student");
         break;
      case R.id.radio_button2:
         if (checked)
         db.insert("","","","","","","Teacher");
         break;
   }
}

login.setOnClickListener(new View.OnClickListener() {
   @Override
   public void onClick(View v) {
      String username = user.getText().toString();
      String password = passw.getText().toString();
      boolean chkemailpass = db.emailpassword(username,password);
      if(chkemailpass==true){
         Toast.makeText(getApplicationContext(),"Successfully Login",Toast.LENGTH_SHORT).show();
         startActivity(new Intent(MainActivity.this, Home.class));
      }else{
      Toast.makeText(getApplicationContext(),"Wrong Username or Password",Toast.LENGTH_SHORT).show();
      }
   }
});