Create restful invites controller and ajaxified the workflow.

app/controllers/invites_controller.rb

@@ -0,0 +1,26 @@
+class InvitesController < ApplicationController
+
+  before_filter :authenticate_membership_or_admin, :only => [:new]
+  #TODO: auhtorize also for create action.
+  
+  def new
+    @invite = Invite.new(:user => @current_user, :group => @group)
+
+    render :update do |page|
+      page.replace_html :edit_box, :partial => "new"
+      page.show :edit_box
+    end
+  end
+  
+  def create
+    @invite = Invite.new(params[:invite])
+
+    render :update do |page|
+      if @invite.save
+        page.replace_html :edit_box, :partial => "success"
+      else
+        page.replace_html :edit_box, :partial => "new"
+      end
+    end
+  end
+end