Nodes Not effecting render?

Support Compositing and Post Processing
1

Hello , I have made a very simple earth and added some composite nodes to try and make a atmosphere effect. However wen i render it the nodes seem to have no effect here is the file:
http://files.filefront.com/earthwith+cloudsblend/;12085684;/fileinfo.html

Also I have tried using the one halo as my atmosphere but it does not really give the desired effect. There is probebly some setting i forget to turn on but i’m pretty new to nodes so i can’t seem to solve the problem.
Thanks
oh also any other node layouts for an atmosphere or perhaps techniques would also be appreciated.

edit :apologies i have fixed issue now sorry for wasting time

2

Click Do Composite in the Anim panel, Render Context.
In the Node Editor header, click Use Nodes.
Select Blender Internal as your renderer..

thats a strange, neat planet. Yafray does not know how to do Blender nodes

3

The day that happens will be a happy day indeed.

4

Yea after posting this i found a vid which in the description revealed how to make the nodes work thanks for the response though