<% link = custom_field.value.match(%r{^[0-9]+$}) ? "http://www.facebook.com/profile.php?id=#{custom_field.value}" : "http://www.facebook.com/#{custom_field.value}" %> <% facebook = link.gsub(%r{^http://}, '') %> <%= link_to(h(facebook), link, :class => 'external') %>