Retrieve associated errors in form

_changePassword.html.erb

<%= form_for @customer do |c| %>
	<% if @customer.errors.any? %>
		<div class="form_errors">
			<ul>
				<% @customer.errors.full_messages.each do |msg| %>
					<li>
						<%= msg %>
					</li>
				<%end%>
			</ul>
		</div>
	<% end %>
	<% if :authentication %>
		<%= fields_for @customer.authentication do |a| %>
			<%= a.label :password %>
			<%= a.password_field :password %>
			<br />
			<%= a.label :password_confirmation%>
			<%= a.password_field :password_confirmation %>
		<% end %>
		<br />
	<% end %>
	<%= c.submit "Save your changes"%>
<% end %>

customer_controller.rb

dbCustomer = Customer.find_by_id(params[:id])
    if dbCustomer.authentication
      if dbCustomer.authentication.login_count == nil
        #This is the first time entering the website after signup
        success = dbCustomer.authentication.update_password(params[:authentication][:password],params[:authentication][:password_confirmation])
        if success[0]
          dbCustomer.authentication.increment!(:login_count)
          flash[:notice] = success[0][:message]
          #redirect_to root_path
        else
          @customer = dbCustomer
          render :action => :edit, :notice => "success.to_s"
        end
    end

output.html

					<h2>Please submit your personal password:</h2>
			<form accept-charset="UTF-8" action="/customers/2110001" class="edit_customer" id="edit_customer_2110001" method="post"><div style="margin:0;padding:0;display:inline"><input name="utf8" type="hidden" value="&#x2713;" /><input name="_method" type="hidden" value="put" /><input name="authenticity_token" type="hidden" value="LiCv6shHTr8gXVk/fNPmhGk2pJ2uUM2WmQ0mm0OWeLs=" /></div>
		
			<div class="field_with_errors"><label for="authentication_password">Password</label></div>
			<div class="field_with_errors"><input id="authentication_password" name="authentication[password]" size="30" type="password" /></div>
			<br />
			<label for="authentication_password_confirmation">Password confirmation</label>
			<input id="authentication_password_confirmation" name="authentication[password_confirmation]" size="30" type="password" />
		<br />
	<input name="commit" type="submit" value="Save your changes" />

Problem:
When updating the password, it should give the a message what the error is... but it doenst give anything...
How do I display the authentication error?