Android studio intent 화면전환

Manifest
<activity android:name=".SubActivity"/> <!--액티비티 추가시 <application> 안에 추가해줘야함-->

MainActivity.class
package com.example.user.intent;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {

public static final int sub = 1001; /*다른 액티비티를 띄우기 위한 요청코드(상수)*/
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

Button button = (Button)findViewById(R.id.sub); /*페이지 전환버튼*/

button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(getApplicationContext(),SubActivity.class);
startActivityForResult(intent,sub);//액티비티 띄우기
}
});
}
}