rails [error_messages_for]

class Foo < ActiveRecord::Base
  unloadable
  validates_presence_of :subject
  validates_length_of :subject,:maximum => 255
end

  def create
    @foo =Foo.new(params[:foo])
    @foo.project_id =@project.id
    if @foo.save
      flash[:notice] = l(:notice_successful_create)
      if params[:continue]
        redirect_to :action=>'new'
      else
        redirect_to :action=>'show',:id=>@foo.id
      end
    else
      respond_to do |format|
        format.html { render :action => 'new' }
        format.api  { render_validation_errors(@foo) }
      end
    end
  end