Date_select javascript_tag

Hi

this is ok

Documento
<%= text_field ‘entry’, ‘nr_documento’ %>

<%= javascript_tag render(:update) { |page|
page[‘entry_nr_documento’].focus } %>

this no

Data
<%= date_select ‘entry’, ‘data’, :order => [:day, :month, :year],
:start_year => 2006 %>
<%= javascript_tag render(:update) { |page| page[‘entry_data’].focus }
%>

err $(“entry_data”) has no properties

where is the mistake?.
thank