Add Facebook XFBML to WordPress theme HTML

wp_xfbml.php

<?php

function fb_xfbml_js() {
?>
<div id="fb-root"></div>
<script>
(function(d, s, id) {
	var js, fjs = d.getElementsByTagName(s)[0];
	if (d.getElementById(id)) return;
	js = d.createElement(s); js.id = id;
	js.src = "//connect.facebook.net/en_US/all.js#xfbml=1";
	fjs.parentNode.insertBefore(js, fjs);
}
(document, 'script', 'facebook-jssdk'));
</script>
<?php
}
add_action('wp_head','fb_xfbml_js',1);

function add_fb_xml_ns($content) {
	return ' xmlns:fb="http://ogp.me/ns/fb#" ' . $content;
}
add_filter('language_attributes', 'add_fb_xml_ns');