How to check the existence of the User from the Autocomplete in rails

i am using rails 2.3.11. I have a text_field_with_autocomplete thing used inside a form of model blog

        <% remote_form_for :blog, :url => {:controller => "blogs", :action =>"add_blog"} do |f|%>
              <%= f.text_field :title, :class => "admtxt1 wd1 lfloat" %>

               <%= text_field_with_auto_complete "user_login", :login, { :size => 15}, { :url => {:controller => 'users', :action => 'autocomplete_for_blogowners'}, :method => :get, :param_name => 'term', :indicator => "spinner"} %>

                <%= submit_tag "Save", :class => "btn-small margintop10" %>
        <%end%>

In the blogs_controller,add_blog action i have

 def add_blog
   unless params[:blog].nil?
       @blog = Blog.new(params[:blog])
        @user = User.find_by_login(params["user_login"][:login])
        @blog.owner = @user
   end

  respond_to do |format|
    if @blog.save
           @saved = true
           format.js { render :action => 'add_blog' }
    else
           @saved = nil
           format.js { render 开发者_高级运维:action => 'add_blog' }
    end
  end
 end

In my add_blog.js.rjs file

     if @saved.nil?
           page.replace_html 'message','<div id="msg" class = "textcolor3">' + @blog.errors.full_messages.join('<br />') + '</div>'
     else
             page.replace_html 'message','<div id="msg" class = "h3txt textcolor3"> Blog created successfully </div>'
     end

My blog tablehas id,title,owner_id

And my model has the validation validates_presence_of :owner_id, :title

The above code works perfectly with the validation of owner shouldnt be blank

But it didnt checks for the wrong user

For eg. if i am typing something where such a user doesn't exists .In that case if i am submitting the form with no results found in the box , Even tat time i am getting Owner shouldn't be blank.

How to check the existence of the User in this case and to add that in the error messages.

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Your code is very strange. Why don't you use Rails 3? Why don't you use REST and CRUD ? Sorry but it is better to rewrite code absolutely.

It seems as php code, have you used php?