How can I put a sidebar in a f.selec?

Rails
1

I have this code:

Client


<% @clients.each do |client| %>
<option value="<%= client.id %>"
<%= ’ selected’ if client.id == @repair_ticket.client_id %>>
<%= client.name%>

<% end %>

I want to put a sidebar in this list. How can I do that?