function disable_billing() {
	if (document.checkout.same_as.checked) {
		document.checkout.first_name.disabled = true;
		document.checkout.last_name.disabled = true;
		document.checkout.address.disabled = true;
		document.checkout.address_2.disabled = true;
		document.checkout.city.disabled = true;
		document.checkout.state.disabled = true;
		document.checkout.zip.disabled = true;
		document.checkout.phone_1.disabled = true;
		document.checkout.phone_2.disabled = true;
		document.checkout.phone_3.disabled = true;
	} else {
		document.checkout.first_name.disabled = false;
        document.checkout.last_name.disabled = false;
        document.checkout.address.disabled = false;
        document.checkout.address_2.disabled = false;
        document.checkout.city.disabled = false;
        document.checkout.state.disabled = false;
        document.checkout.zip.disabled = false;
        document.checkout.phone_1.disabled = false;
        document.checkout.phone_2.disabled = false;
        document.checkout.phone_3.disabled = false;
	}
}