args.putString("CID ", p1);
key is CID
This
String id=getArguments().getString("p1");
Should be
String id=getArguments().getString("CID");
Edit :
I am trying to pass a value from one fragment to another
I din't notice its Fragment to Fragment Communication.
You need to use interface as a call back to the activity. Then communicate value to other fragment
http://developer.android.com/training/basics/fragments/communicating.html
Quoting docs
Often you will want one Fragment to communicate with another, for example to change the content based on a user event. All Fragment-to-Fragment communication is done through the associated Activity. Two Fragments should never communicate directly.