highlight and pagination

I made a search-field which shows all hits and highlights the all
words searched for:

  def suche

          if params[:link][:suchfeld] == "description"
              @description = "show"
              @highlight = params[:suche]
          end

        @link_pages, @links =
            paginate :link, :order_by => 'url',
            :conditions => ["#{params[:link][:suchfeld]} LIKE ?",
"%"+params[:suche]+"%"],
            :include => [:member],
            :per_page => 3

  end

view:

<% if @description %>
<div class="link_initial_description" id="link<%= link.id %>">
<%= highlight(link.description, @highlight, highlighter = '<strong
class="highlight">\1</strong>') %>
</div>
<% else %>
<div class="link_initial_description" style="display:none"
id="link<%= link.id %>">
<%= link.description %>
</div>
<% end %>
<%= pagination_links(@link_pages) %>

Everything works fine when I get only 1 result page. When I get
more pages and click the pages_link highlighting no longer works.

You have a nil object when you didn't expect it!
You might have expected an instance of Array.
The error occurred while evaluating nil.[]

WHat can I do?

Thanx

Sounds like when you go to the second page, you no longer have
params[:link][:suchfeld] set.

Also, there may not be a reason to set @highlight = params[:suche].
The params are available to the View and you can just do:
<%= highlight(link.description, params[:suche], highlighter = '<strong
class="highlight">\1</strong>') %>

But I think your problem isn't the highlighting, it's that the action
suche is expecting params[:link][:suchfeld].

HTH,
Kevin