Drupal commerce hide billing address fields when giftcard added to make order free

gistfile1.js

	/**
	 * function to remove billing fields from display if giftcard / coupon makes order total £0.00
	 */
	$(document).ready(function(){
		// on change due to ajax
		$( document ).ajaxComplete(function() {
		  console.log( "Triggered ajaxComplete handler." );
		  var orderTotal = $('.page-checkout .view-id-commerce_cart_summary .field-name-commerce-order-total .component-type-commerce-price-formatted-amount .component-total').text();
		  if(orderTotal == '£0.00'){
		  	console.log('Order total is zero (var: ' + orderTotal + ')');
		  	// hide the .field-name-commerce-customer-address container contents
		  	$('.form-item-customer-profile-billing-commerce-customer-address-und-0-country').hide(); // this will have a default value anyway
		  	$('.street-block, .locality-block').hide();

		  	// set all fields in .field-name-commerce-customer-address to value = 'Free order - no billing details needed'
		  	if( !$('input.thoroughfare').val() ) { // because it might be pre-filled from a previous order
		  		$('input.thoroughfare').val('Free order - no info required');
		  	}
		  	if( !$('input.locality').val() ) { // because it might be pre-filled from a previous order
		  		$('input.locality').val('Free order - no info required');
		  	}
		  	if( !$('input.postal-code').val() ) { // because it might be pre-filled from a previous order
		  		$('input.postal-code').val('E8 3PH'); // bakery address
		  	}
		  	// @TODO replace it with some text like "Free order - no billing information required"
		  }
		});
	});