title: Showing error messages in active admin for has many relationship table
body: <p>I am facing an issue showing up the error messages in active admin.</p>
  
  <p>I get all the error messages displayed with the fields in the form.
  But in the code below, I need atleast one skill and maximum 5 skills to be added.
  Else need to throw an error message.</p>
  
  <p>I've added a validation in model as :</p>
  
  <p>validates :skills, :length => { :minimum => 1, :maximum => 5,
                                     :message => " should be atleast 1 and less than 5"}</p>
  
  <p>This validates perfectly, but no error message is displayed.</p>
  
  <p>Can anyone help me with the display of the error message.</p>
  
  <p>Following is the code :</p>
  
  <pre><code>form :html =&gt; { :enctype =&gt; "multipart/form-data" } do |f|
  
      f.inputs "User", :multipart =&gt; true do
  
          f.input :name
          f.input :email,  :as =&gt; :email
          f.input :profile_name
          f.input :date_of_birth
          f.input :gender,  :as =&gt; :select, :collection =&gt; Gender::GENDERS
        end
        f.inputs "Skills* ( minimum 1 &amp; maximum 5 )" do
          f.has_many :skills do |p|
            if !p.object.nil?
              # show the destroy checkbox only if it is an existing appointment
              # else, there's already dynamic JS to add / remove new appointments
              p.input :_destroy, :as =&gt; :boolean, :label =&gt; "Destroy?",
                      :hint =&gt; "Check this checkbox, if you want to delete this field."
            end
            p.input :description
            p.input :title
          end
        end
      end
    end
  </code></pre>