autocompete for first_name OR last_name

My autocomplete method searches only on the last_name column but I'd like for it to search first_name and last_name for a match. Basically how gmail and yahoo mail beta does it. I tried the sql OR operator but I can't get it to work.

def autocomplete     search = params[:user]     @users = User.find(:all,        :conditions => [ 'LOWER(last_name) LIKE ?',        '%' + search.downcase + '%' ],        :order => 'last_name ASC',        :limit => 8) unless search.blank?     render :partial => "search"   end

Thanks for any help!

I see where I went wrong. Works perfect, thanks!