title: MainActivity.java error on running the app on phone
body: <p>I have made a new app on adt and now I want to run it on my phone, but It says there are two errors. Both errors are about R in <code>src &gt; com.example.myfirstapp&gt;MainActivity.java</code>  </p>
  
  <p>This is my code :</p>
  
  <pre><code>package com.example.myfirstapp;
  
  import android.os.Bundle;
  import android.app.Activity;
  import android.view.Menu;
  
  public class MainActivity extends Activity {
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
      }
  
  
      @Override
      public boolean onCreateOptionsMenu(Menu menu) {
          // Inflate the menu; this adds items to the action bar if it is present.
          getMenuInflater().inflate(R.menu.main, menu);
          return true;
      }
  
  }
  </code></pre>