def paginate(collection, controller, action)
  return if collection.empty?
  if collection.total_pages > collection.per_page
    html = 1.upto(collection.total_pages).map { |i|
      options = { :page => i }
      options.merge!(:q => params[:q]) if params[:q].present?
      link_to(i, url(controller, action, options), :class => [(params[:page].to_i == i ? :current : :page), ' link'])
    }.join
    content_tag(:div, html, :class => "pagination")
  end
end