Script Menu Utama Android

package com.example.apps;

import java.util.ArrayList;

public class menuutama extends Activity {

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.menuutama);
//
ImageView btnbarang= (ImageView) findViewById(R.id.btnbarang);
btnbarang.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
Intent i = new Intent(getApplicationContext(), List_barang.class);
startActivityForResult(i, 100);
}});

ImageView btncustomer= (ImageView) findViewById(R.id.btncustomer);
btncustomer.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
Intent i = new Intent(getApplicationContext(), List_customer.class);
startActivityForResult(i, 100);
}});

ImageView btnsupplier= (ImageView) findViewById(R.id.btnsupplier);
btnsupplier.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
Intent i = new Intent(getApplicationContext(), List_supplier.class);
startActivityForResult(i, 100);
}});

ImageView btnorder= (ImageView) findViewById(R.id.btnorder);
btnorder.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
Intent i = new Intent(getApplicationContext(), List_order.class);
startActivityForResult(i, 100);
}});

  }

public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
finish();
return true;
}
return super.onKeyDown(keyCode, event);
}   
}