Template structure oke ?

Hi,

In my layout/application.rhtml there is a form for finding/cheching
airline-tickets online.

The value in the form is filled in based on the destination.name

<% form_for @destination do |f| %>
     <%= f.text_field :name %>
  <% end %>

But when i go to a page that is not a destination i get an error message
because there is no (params[:id] of destination.

How can i resolve this problem..with conditions ? or is my
template-scructure not oke?

remco