Fix order button

package com.example.android.justjava;

import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.widget.TextView;

import java.text.NumberFormat;

public class MainActivity extends ActionBarActivity {

	int quantity = 2;
	
	@Override
	protected void onCreate(Bundle savedInstanceState){
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
	}

	public void increment(View view){
		quantity = quantity + 1;
		display(quantity);
	}

	public void decrement(View view){
		quantity = quantity - 1;
		display(quantity);
	}

	public void submitOrder(View view){
		displayPrice(quantity * 5);
	}

	private void display(int number){
		TextView quantityTextView = (TextView) findViewById(
			R.id.quantity_text_view);
		quantityTextView.setText("" + number);
	}

	private void displayPrice(int number){
		TextView priceTextView = (TextView) findViewById(R.id.price_text_view);
		priceTextView.setText(NumberFormat.getCurrencyInstance().format(number));
	}
}

<LinearLayout xmlns:android="http://schemas.android."
	xmlns:tools="http://schemas.android.com/tools"
	android:layout_width="match_parent"
	android:layout_height="match_parent"
	android:paddingBottom="@dimen/activity_vertical"
	android:paddingLeft="@dimen/activity_horizontal"
	android:paddingRight="@dimen/activity_horizontal"
	android:paddingTop="@dimen/activity_vertical"
	android:orientation="vertical"
	tools:context=".MainActivity">

	<TextView
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"
		android:layout_marginBottom="16dp"
		android:text="Quantity" 
		android:textAllCaps="true" />

 	<Button
   	 android:layout_height="48dp"
     android:layout_width="48dp"
     android:text="+"
     android:onClick="increment" />

	<TextView
		android:id="@+id/quantity_text_view"
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"
		android:text="0"
		android:textSize="16sp"
		adnroid:textColor="@android:color/black" />

 	<Button
   	 android:layout_height="48dp"
     android:layout_width="48dp"
     android:text="-"
     android:onClick="decrement" />

	<TextView
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"
		android:layout_marginTop="16dp"
		android:text="Price" 
		android:textAllCaps="true" />

	<TextView
		android:id="@+id/price_text_view"
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"
		android:layout_marginTop="16dp"
		android:text="$0"
		android:textSize="16sp"
		adnroid:textColor="@android:color/black" />

 	<Button
   	 android:layout_height="wrap_content"
     android:layout_width="wrap_content"
     android:layout_marginTop="16dp"
     android:text="Order"
     android:onClick="submitOrder" />

</LinearLayout>