I want to place my three buttons above the admob ad which is in a relativelayout. 
The ad is overlapping the buttons whereas I want the ad to display below the buttons.

```
<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent" android:layout_height="fill_parent"
    android:background="#ffffff" android:id="@+id/puzzlelayout">

    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:orientation="vertical" android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true" android:layout_alignParentBottom="true"
        android:id="@+id/puzzlelayout1">

        <Button android:layout_width="wrap_content"
            android:layout_height="wrap_content" android:id="@+id/btn3"
             android:background="@drawable/custom_quiz_button"></Button>

        <Button android:layout_width="wrap_content"
             android:layout_height="wrap_content"
            android:id="@+id/btn2" 
            android:layout_toRightOf="@+id/btn3" android:visibility="visible"
            android:background="@drawable/custom_quiz_button"></Button>

        <Button android:layout_width="wrap_content"
             android:layout_height="wrap_content"
            android:id="@+id/btn1" android:layout_toRightOf="@+id/btn2"
            android:background="@drawable/custom_quiz_button"></Button>

    </RelativeLayout>

    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_below="@+id/puzzlelayout1" android:layout_width="fill_parent"
        android:layout_height="fill_parent" android:id="@+id/linearLayout02" android:layout_alignParentBottom="true"
        >
    </RelativeLayout>
</RelativeLayout>

```