* chat mesages by scope in admin

admin/app/admin/chat_messages.rb

@@ -9,6 +9,12 @@ ActiveAdmin.register JamRuby::ChatMessage, :as => 'ChatMessage' do
 
   config.sort_order = 'created_at DESC'
 
+  scope("Global", default:true) { |scope|
+    scope.where("channel = 'global'")
+  }
+  scope("Session", ) { |scope|
+    scope.where("channel = 'session'")
+  }
   index do
     column 'User' do |oo| link_to(oo.user.email, oo.user.admin_url, {:title => oo.user.email}) end
     column "Timestamp" do |post|