rendering a javascript script error...

I a using a jQueryUI dialog box which renders very well html code

search.html.haml =====
- content_for :main_content do
  #content
    = form_tag query_plan_day_meals_path(:plan_id => @plan, :day_id =>
@day), :remote => true do
      #error_messages{:style => "display: none;"}
                        .... form fields

I am now trying to render a javascript block given by our partner

search.html.haml =====
- content_for :main_content do
  #content{:style => "width:300px;"}
    = render :partial => "myscript"

_myscript.html.erb
<script src="http://platform.fatsecret.com/js/?
key=xxxxxxxxxxx&amp;auto_load=true"></script>

the dialog form is open correctly, but the script is not rendered in
it .. ( #content div is empty)
and no error message .. no request to this url...

why I am wrong ?
thanks for your feedback