Andriod Maps - Class Error

[pinkfloydim]

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#FFFFFF"
tools:context=".TownMapActivity" >

<fragment
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.google.android.gms.maps.MapFragment" />

<!-- Tab Section -->

<include layout="@layout/tab_section" />

</RelativeLayout>

Now this gives me :

java.lang.ClassNotFoundException: com.google.android.gms.maps.MapFragment

I have included the google-play-services.jar, and can see that class, but it always crashes the app.

Any ideas how to fix, have followed all the stuff on the andriod dev site, and can't get my map to load at all.

 

[pinkfloydim]

Actually needed to add an external library into the build to get this to work. Not mentioned in the andriod docs. SO live and learn.