i cannot go to another page and please solve the problem for me.

Button signin;
EditText editTextUsername,editTextPassword;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

    signin=(Button)findViewById(R.id.login);
    editTextUsername=(EditText)findViewById(R.id.username);
    editTextPassword=(EditText)findViewById(R.id.password);

    signin.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String username=String.valueOf(editTextUsername);
            String password=String.valueOf(editTextPassword);

            if(username.equals("admin") && password.equals("admin"))
            {
                Intent intent=new Intent(MainActivity.this,SecondPage.class);
                startActivity(intent);
            }
            else
            {
                Intent intent=new Intent(MainActivity.this,MainActivity.class);
            }

        }
    });
}

i can't go to next page.