<%= bootstrap_form_tag(url: admin_path, method: :post, layout: :inline) do |f| %>
<%= f.select(:days_back, [['1 week', 7], ['2 weeks', 14], ['1 month', 30]], selected: params[:days_back]) %>
<%= f.submit 'See Stats', class: "btn btn-primary" %>
<% end %>