title: NullPointerException error
body: <p>My Logcat </p>
  
  <pre><code>08-06 01:27:34.874: ERROR/AndroidRuntime(721): Uncaught handler: thread main exiting due to uncaught exception
  08-06 01:27:34.893: ERROR/AndroidRuntime(721): java.lang.NullPointerException
  08-06 01:27:34.893: ERROR/AndroidRuntime(721):     at one.two.Booking$MyOnItemSelectedListener.onItemSelected(Booking.java:53)
  08-06 01:27:34.893: ERROR/AndroidRuntime(721):     at android.widget.AdapterView.fireOnSelected(AdapterView.java:856)
  08-06 01:27:34.893: ERROR/AndroidRuntime(721):     at android.widget.AdapterView.access$200(AdapterView.java:41)
  08-06 01:27:34.893: ERROR/AndroidRuntime(721):     at android.widget.AdapterView$SelectionNotifier.run(AdapterView.java:827)
  08-06 01:27:34.893: ERROR/AndroidRuntime(721):     at android.os.Handler.handleCallback(Handler.java:587)
  08-06 01:27:34.893: ERROR/AndroidRuntime(721):     at android.os.Handler.dispatchMessage(Handler.java:92)
  08-06 01:27:34.893: ERROR/AndroidRuntime(721):     at android.os.Looper.loop(Looper.java:123)
  08-06 01:27:34.893: ERROR/AndroidRuntime(721):     at android.app.ActivityThread.main(ActivityThread.java:3948)
  08-06 01:27:34.893: ERROR/AndroidRuntime(721):     at java.lang.reflect.Method.invokeNative(Native Method)
  08-06 01:27:34.893: ERROR/AndroidRuntime(721):     at java.lang.reflect.Method.invoke(Method.java:521)
  08-06 01:27:34.893: ERROR/AndroidRuntime(721):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:782)
  08-06 01:27:34.893: ERROR/AndroidRuntime(721):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:540)
  08-06 01:27:34.893: ERROR/AndroidRuntime(721):     at dalvik.system.NativeStart.main(Native Method)
  </code></pre>
  
  <p>Booking.java</p>
  
  <pre><code>package one.two;
  
  import android.app.Activity;
  import android.database.Cursor;
  import android.os.Bundle;
  import android.view.View;
  import android.widget.AdapterView;
  import android.widget.SimpleCursorAdapter;
  import android.widget.Spinner;
  import android.widget.TextView;
  import android.widget.AdapterView.OnItemSelectedListener;
  
  
  public class Booking extends Activity
  {
      private DBAdapter db; 
      private Spinner colourSpinner;
      public Cursor c;
      public TextView txtArrival;
      /** Called when the activity is first created. */
      public void onCreate(Bundle savedInstanceState)
      {
          super.onCreate(savedInstanceState);
          db = new DBAdapter(this);
          this.setContentView(R.layout.booking);
          db.open();
          fillData();
          db.close();
          TextView txtArrival = (TextView) findViewById(R.id.txtArrival);
          Spinner colourSpinner = (Spinner) findViewById(R.id.myspinner);
          colourSpinner.setOnItemSelectedListener(new MyOnItemSelectedListener());
      }
  
      private void fillData()
      {
          c = db.getSpinnerData();
          startManagingCursor(c);
          String[] from = new String[]{DBAdapter.KEY_ARRIVAL};
          int[] to = new int[]{android.R.id.text1};
          SimpleCursorAdapter adapter =
          new SimpleCursorAdapter(this,R.layout.booking, c, from, to );
          adapter.setDropDownViewResource( android.R.layout.simple_spinner_dropdown_item );
          Spinner colourSpinner = (Spinner) findViewById(R.id.myspinner);
          colourSpinner.setAdapter(adapter);
      }
      public class MyOnItemSelectedListener implements OnItemSelectedListener
      {
          public void onItemSelected(AdapterView&lt;?&gt; arg0, View v,int position, long id)
          {
              boolean result = Booking.this.c.moveToPosition(position);
              if (result) {
                  String title=Booking.this.c.getString(1);
                  Booking.this.txtArrival.setText(title);
              }
  
          }
          @Override
          public void onNothingSelected(AdapterView&lt;?&gt; arg0)
          {
              // TODO Auto-generated method stub
  
          }
      };
  }
  </code></pre>
  
  <p>I would like to know how to solve this error.
  Thank you.</p>