How to support the backward compatibility in Android app deployment?

The code developed with new versions of the android SDK can be run on the older version using the following specification in the AndroidMainfest.xml

<uses-sdk android:minSdkVersion="8" android:targetSdkVersion="15"/>

In addition to this you need to create a directory in your project as libs (parallel to src) and copy the android-support-v4.jar from the android -support package installed.

After copy the lib file you need to add that into the build path by right click on the lib file in eclipse and click on Build Path -> Add Build Path