<div class="account-forms">
{%- form 'create_customer' -%}
<input type="hidden" id="customer_tags" name="customer[tags]" value="new"/>
{{- form.errors | default_errors -}}

<div class="account-forms">
  <div id="CustomerLoginForm">
    {%- form 'customer_login' -%}
      {%- if customer.orders_count != 0 -%}
         <input type="hidden" id="customer_tags" name="customer[tags]" value="existing"/>
      {% else %}
          <input type="hidden" id="customer_tags" name="customer[tags]" value="test"/>
       {% endif %}
{{- form.errors | default_errors -}}