Android : How to get AdMob banner to show up at the bottom of the app?

How to get AdMob banner to show up at the bottom of the app? I tried different methods that were posted here and no matter what I do the ad appears on top of the app. What am I doing wrong?

Here is what my layout looks like

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:ads="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
tools:context="${relativePackage}.${activityClass}" >

<EditText
    android:id="@+id/vinText"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true"
    android:ems="7"
    android:gravity="center"
    android:inputType="textCapCharacters"
    android:maxLength="7"
    android:selectAllOnFocus="true" >

    <requestFocus />
</EditText>

<Button
    android:id="@+id/button1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/vinText"
    android:layout_centerHorizontal="true"
    android:onClick="sendVIN"
    android:text="@string/button_send" />


<LinearLayout
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:gravity="center">

    <com.google.android.gms.ads.AdView
        android:id="@+id/adView"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        ads:adSize="SMART_BANNER"
        ads:adUnitId="ID" >
    </com.google.android.gms.ads.AdView>
</LinearLayout>


</RelativeLayout>