title: App crashes when opening a class which contains a ListView
body: <p>I have the following class which as you can see contains a EditText, Button and list.
  I want the user to type in the EditText some text,click Search and Show up the results from </p>
  
  <pre><code>SQLite database in the list below the button/edittext field.
  public class FindOrder  extends ListActivity {
  private List&lt;String&gt; arr;
  private ListView listView;
  Button search;
  EditText search_field;
  String search_val;
  SQLiteDatabase db = null;
  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.find_order);
      // TODO Auto-generated method stub
      Log.e("myTag","in func");
      search = (Button) findViewById(R.id.search_button);
      search_field = (EditText) findViewById(R.id.search_field);
      search.setOnClickListener(  
              new View.OnClickListener() {
                  public void onClick(View view) {
                      search_val=search_field.getText().toString();
                      //getOrder(search_val);
  
                  }
              });
  }
  
  public void getOrder(String val) {
      Log.e("myTag","in func");
      String query;
      String[] s_arr = new String[1];
      listView = (ListView) findViewById(R.id.listView);
      ArrayAdapter&lt;String&gt; adapter;
      arr = new ArrayList&lt;String&gt;();
      db =  this.openOrCreateDatabase( "DBname", MODE_PRIVATE, null);
      query="SELECT OrderName, OrderLink, DateYear, DateMonth, DateDay, OrderPrice FROM Orders where OrderName=?";
      s_arr[0]=val;
      Cursor c = db.rawQuery(query, s_arr);
      if (c != null ) {
         if  (c.moveToFirst()) {
             do {     
                 arr.add(c.getString(c.getColumnIndex(DatabaseHelper.colName)));
                 Log.e("myTag",c.getString(c.getColumnIndex(DatabaseHelper.colName)));
             } while (c.moveToNext());
         }
     } 
     c.close();
    //setListAdapter(new ArrayAdapter&lt;String&gt;(this, android.R.layout.simple_list_item_1,arr));
    adapter = new ArrayAdapter&lt;String&gt;(this,android.R.layout.simple_list_item_1, arr);
    listView.setAdapter(adapter);
    TextView textview = new TextView(this);
    LinearLayout ll2 = (LinearLayout)findViewById(R.id.linearLayout2);
    ll2.addView(textview);
  
  }
  }
  </code></pre>
  
  <p>Currently whenever i click on the button in Main Menu which leads to this activity, i get an FC.
  One of the errors i can see i the log is :</p>
  
  <pre><code>06-02 10:32:18.387: E/AndroidRuntime(1904): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.Sagi.MyOrders/com.Sagi.MyOrders.FindOrder}: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list'
  </code></pre>
  
  <p>Together with many other errors . <strong>But i couldn't really understand why should i have .list attribute ...</strong></p>
  
  <p>XML :</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent" &gt;
      &lt;LinearLayout
          android:id = "@+id/linearLayout1"
          android:orientation="horizontal"
          android:layout_width="fill_parent"
          android:layout_height="wrap_content"&gt;
          &lt;EditText
                  android:id="@+id/search_field"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:ems="10" &gt;
          &lt;/EditText&gt;
          &lt;Button
              android:id="@+id/search_button"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:text="Search" /&gt;
      &lt;/LinearLayout&gt;
      &lt;LinearLayout
          android:id = "@+id/linearLayout2"
          android:orientation="vertical"
          android:layout_width="fill_parent"
          android:layout_height="wrap_content"&gt;
      &lt;/LinearLayout&gt;
      &lt;ListView
              android:id="@+id/listView"
              android:layout_width="fill_parent"
              android:layout_height="wrap_content"/&gt;
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p><strong>Thanks !</strong></p>