rhodecode/templates/base/flash_msg.html

<div class="flash_msg">
    <% messages = h.flash.pop_messages() %>
    % if messages:
        % for message in messages:
            <div class="alert alert-dismissable alert-${message.category}">
              <button type="button" class="close" data-dismiss="alert" aria-hidden="true">&times;</button>
              ${message}
            </div>
        % endfor
    % endif
    <script>
    if (typeof jQuery != 'undefined') {
        $(".alert").alert();
    }
    </script>
</div>