# POST /groups
  # POST /groups.json
  def create

   @group = Group.new(params[:group])

s = @group.shares.build(...) #<<not working coz group id is not present


    respond_to do |format|
      if @group.save

        s = @group.shares.build(...) #<<what to do with group if share is not valid?

        format.js { }
      else
        format.js# {   @group}
      end
    end
  end