{% extends "checkout/checkout.html" %}

{% block title %}
Order preview | {{ block.super }}
{% endblock %}

{% block checkout-nav %}
	{% include 'checkout/nav.html' with step=4 %}
{% endblock %}

{% block place_order %}
<h3>Please review the information above, then click "Place Order"</h3>
<form method="post" action="{% url checkout:preview %}">
	<input type="hidden" name="action" value="place_order" />
	{% csrf_token %}
    <div class="form-actions">
        <button id='place-order' type="submit" value="Place order" class="pull-right btn btn-primary btn-large js-disable-on-click">Place order</button>
    </div>
</form>
{% endblock place_order %}

{% extends "checkout/checkout.html" %}

{% block title %}
Order preview | {{ block.super }}
{% endblock %}

{% block checkout-nav %}
	{% include 'checkout/nav.html' with step=4 %}
{% endblock %}

{% block place_order %}
<h3>Please review the information above, then click "Place Order"</h3>
<form method="post" action="{% url checkout:preview %}" id="place-order-form">
	<input type="hidden" name="action" value="place_order" />
	{% csrf_token %}
    <div class="form-actions">
        <button id='place-order' type="submit" value="Place order" class="pull-right btn btn-primary btn-large js-disable-on-click">Place order</button>
    </div>
</form>
{% endblock place_order %}

Add form id being used in checkout.js
Add form id being used in checkout.js
