从未调用过Rails 3 js.erb

I'm trying to keep the user on the same page and execute some Javascript after an Update is performed..

However my js.erb never seems to get called and instead I get redirected to the route "http://localhost:3000/upload_images/id" and my firebug console produces...

"NetworkError: 406 Not Acceptable -http://localhost:3000/upload_images/id"

Update Action

    def update  
    @upload_image = UploadImage.find(params[:id])
    #If this image is set as the preview restore all associated images to default
    if params[:upload_image][:preview] == "1"
      other_uploads = @upload_image.upload.upload_images.where("not upload_images.id = ?", @upload_image.id)
      other_uploads.each do |upload_image|
        upload_image.preview = "0"
        upload_image.save
      end
    end      
    respond_to do |format|    
      if @upload_image.update_attributes(params[:upload_image])
        #keep the user on current page and call some Javascript
        format.js{render :template => 'update.js.erb'}
      else
        format.html { render action: "edit" }
        format.json { render json: @upload_image.errors, status: :unprocessable_entity }
        format.js
      end
    end
  end

Update.js.erb

alert("hello world!");

Edit form

<%=form_for(@upload_image) do |f| %>
   ....
<% end %>

It's not important for me to see the live updates, I don't mind if the user has to refresh to see them. I just want to keep the page state as is (with the exception of some changes made by JQuery) and make a post to the database.

You probably need to switch to a remote form:

<%= form_for(@upload_image, :remote => true) do |f| %>

Otherwise your form will attempt an HTTP POST that expects an HTTP response.