problem with include_blank

Hi,

I've got a 'easy' question. I have a formular with a datetime field and I want blank field with a white space - char because the normal way with :include_blank is not w3c - conform. Has anyboy an idea?

I use this but it don't fit:

<%= f.label :unpublished_on, "#{:unpublished_on.l}:" %> <%= f.datetime_select :unpublished_on,                     :use_month_numbers => true,                     :minute_step => 15,                     :include_blank => "&nbsp;", # <-- this one                     :order => [:day, :month, :year]                      %>

Regards, Eddy