title: Switching from portrait to landscape NullPointerException
body: <p>I am using the layout posted below. I have the same file (same filename as well) in both Res/layout and Res/layout-land. Whenever I switch the orientation in my emulator, it always throws a NullPointerExeption. The logcat says it has a "FATAL ERROR" and a "NullPointerException". It worked when I didn't have the layout-land file, so I'm not sure what the issue is. Am I supposed to put the file in a Res/layout-port for portrait instead of the default Res/layout folder? Thanks in advance. </p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:orientation="vertical" &gt;
  
   &lt;ScrollView
      android:id="@+id/scrollView1"
      android:layout_width="match_parent"
      android:layout_height="wrap_content" &gt;
  
      &lt;LinearLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content" &gt;
  
          &lt;ListView
              android:id="@+id/tasklistview"
              android:layout_width="match_parent"
              android:layout_height="246dp"
              android:layout_alignParentTop="true"
              android:layout_toRightOf="@+id/enterbtn" &gt;
          &lt;/ListView&gt;
      &lt;/LinearLayout&gt;
  &lt;/ScrollView&gt;
  
  &lt;EditText
      android:id="@+id/entertaskfield"
      android:layout_width="470dp"
      android:layout_height="wrap_content"
      android:layout_alignParentBottom="true"
      android:layout_alignParentLeft="true"
      android:ems="10" /&gt;
  
  &lt;Button
      android:id="@+id/send"
      style="?android:attr/buttonStyleSmall"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignParentBottom="true"
      android:layout_alignParentRight="true"
      android:background="@drawable/send" /&gt;
  </code></pre>
  
  <p></p>
  
  <pre><code>public class MainActivity extends Activity {
  
  public MenuDrawer mDrawer;
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      mDrawer = MenuDrawer.attach(this, Position.BOTTOM);
      mDrawer.setContentView(R.layout.activity_main);
      mDrawer.setMenuView(R.layout.rightmenu);
      ListView myListView = (ListView)findViewById(R.id.tasklistview);
      final EditText myEditText = (EditText)findViewById(R.id.entertaskfield);
      Button enter = (Button)findViewById(R.id.enterbtn);
      Button clearfull = (Button)findViewById(R.id.clearlist);
      Button settings = (Button)findViewById(R.id.aboutbtn);
  
  
  
      // Create the array list of to do items
      final ArrayList todoItems = new ArrayList();
      // Create the array adapter to bind the array to the listview
      final ArrayAdapter aa;
      aa = new ArrayAdapter(this,
      android.R.layout.simple_list_item_1,
      todoItems);
      // Bind the array adapter to the listview.
      myListView.setAdapter(aa);
  
      enter.setOnClickListener(new OnClickListener() {
  
          @Override
          public void onClick(View v) {
              // TODO Auto-generated method stub
                  todoItems.add(0, myEditText.getText().toString());
                  aa.notifyDataSetChanged();
                  myEditText.setText("");
  
  
  
      };
  });
  
  clearfull.setOnClickListener(new OnClickListener() {
  
          @Override
          public void onClick(View arg0) {
              // TODO Auto-generated method stub
              AlertDialog.Builder alertDialog = new AlertDialog.Builder(MainActivity.this);
  
              // Setting Dialog Title
              alertDialog.setTitle("Confirm Deletion");
  
              // Setting Dialog Message
              alertDialog.setMessage("Are you sure you want delete all tasks?");
  
              // Setting Icon to Dialog
              alertDialog.setIcon(R.drawable.delete);
  
              // Setting Positive "Yes" Button
              alertDialog.setPositiveButton("Yep", new DialogInterface.OnClickListener() {
                  public void onClick(DialogInterface dialog,int which) {
                      aa.clear();
                      aa.notifyDataSetChanged();
                  // Write your code here to invoke YES event
                  Toast.makeText(getApplicationContext(), "Tasks Removed", Toast.LENGTH_SHORT).show();
                  }
              });
  
              // Setting Negative "NO" Button
              alertDialog.setNegativeButton("Nope", new DialogInterface.OnClickListener() {
                  public void onClick(DialogInterface dialog, int which) {
                  dialog.cancel();
                  }
              });
  
              // Showing Alert Message
              alertDialog.show();
          }
      });
  
      settings.setOnClickListener(new OnClickListener() {
  
          @Override
          public void onClick(View v) {
              // TODO Auto-generated method stub
              Intent myIntent = new Intent(MainActivity.this, About.class);
              MainActivity.this.startActivity(myIntent);
              overridePendingTransition(R.anim.push_up_in, R.anim.push_up_out);
          }
      });
  
  }
  
  
  }
  </code></pre>