Adding a Notify Me form

Email field.html

<!-- Add this to your product.liquid just after the -->
<p id="notify">
<label>We can send you a one-time email when this product is back in stock. We won't use your address for anything else.</label>
<input type="email" id="notify_me">
<input type="submit" value="Notify me" class="btn button" onclick="BISPopover.create(document.getElementById('notify_me').value, {{variant.id}}).then(function(data) { if (data.status == 'OK') { alert(data.message) } else { alert('Pleasse check your email address is correct and try again.') } }); return false;">
</p>

Show or hide the field.js

// In product.liquid find the line
//  var selectCallback = function(variant, selector) {
// and add this immediately after it

$('#notify').toggle(variant && !variant.available)