How to timeout flash messages in rails

I currently have standard flash messages with the devise gem for success/failure etc. I have added the option to manually close the message with some bootstrap functionality via a close class. A small snippet is shown below.

{ 
  <a class="close" data-dismiss="alert">&#215;</a>
  <%= content_tag :div, msg, :id => "flash_#{name}" %>
}

I was would like to have an option to create a timeout period where the alert message would close on its one after 5 seconds. Not sure if there is a simple way to do this in Rails.

Thanks