title: custom alert dialog not getting displayed
body: <p>I want to display a custom alert dialog whose structure has been defined in an XML file. This is the code I used.</p>
  
  <pre><code>AlertDialog.Builder builder = new AlertDialog.Builder(this);
  builder.setView(findViewById(R.layout.inputform));
  builder.show();
  </code></pre>
  
  <p>It is fired when a button is clicked. However, the window was not getting displayed. I got this transparent grey layer on top of the screen and could not click on anything. Some basic codes like using <code>setMessage</code> or displaying checkboxes work well, though. Can anyone point out where I do wrong?</p>
  
  <pre><code>&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
      android:layout_width="fill_parent" android:layout_height="fill_parent"&gt;
  
  &lt;TableLayout android:id="@+id/TableLayout01"
      android:layout_width="fill_parent" android:layout_height="fill_parent"&gt;
  
  &lt;TableRow android:id="@+id/TableRow01" android:layout_width="fill_parent"
      android:layout_height="fill_parent"&gt;
      &lt;TextView android:text="Room name" android:id="@+id/TextView01"
          android:layout_width="fill_parent" android:layout_height="wrap_content"/&gt;
      &lt;EditText android:hint="Enter room name" android:id="@+id/EditText01"
          android:layout_width="0dp" android:layout_height="wrap_content"
          android:layout_weight="1"/&gt;
  &lt;/TableRow&gt;
  
  &lt;TableRow android:id="@+id/TableRow02" android:layout_width="fill_parent"
      android:layout_height="fill_parent"&gt;
      &lt;TextView android:text="Point id" android:id="@+id/TextView02"
          android:layout_width="fill_parent" android:layout_height="wrap_content"/&gt;
      &lt;EditText android:hint="Enter point id" android:id="@+id/EditText02"
          android:layout_width="0dp" android:layout_height="wrap_content"
          android:layout_weight="1"/&gt;
  &lt;/TableRow&gt;
  
  &lt;TableRow android:id="@+id/TableRow03" android:layout_width="fill_parent"
      android:layout_height="fill_parent"&gt;
      &lt;Button android:text="OK" android:id="@+id/btnOK"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"/&gt;
  &lt;/TableRow&gt;
  
  &lt;/TableLayout&gt;
  &lt;/LinearLayout&gt;
  </code></pre>