A friendly like button

<link rel="stylesheet" href="http://static.ak.fbcdn.net/rsrc.php/zD5ZK/hash/4146lpfk.css" type="text/css" />
<script type="text/javascript">
	var fbURL = PASTE_FACEBOOK_URL_HERE;
	function insertLikeButton() {
		var container = document.getElementById('flbCont');
		var w = container.style.width;
		var h = container.style.height;
		fbFrame = document.createElement("IFRAME"); 
		fbFrame.setAttribute("src", fbURL);
		fbFrame.setAttribute("scrolling", "no");
		fbFrame.setAttribute("frameBorder", 0);
		fbFrame.setAttribute("allowTransparency", true);
		fbFrame.style.border = "none";
		fbFrame.style.overflow = "hidden";
		fbFrame.style.width = w; 
		fbFrame.style.height = h; 
		container.replaceChild(fbFrame, document.getElementById('flb'));
	}
</script>
<div id="flbCont" class="connect_widget">
	<a id="flb" class="connect_widget_like_button clearfix like_button_no_like" onclick="insertLikeButton();" style="cursor:pointer;-moz-outline-style:none;text-decoration:none"><span class="liketext" style="line-height:1">Show Facebook Likes</span></a>
</div>

can u expalin this trick..
u know sir ,"play the video" button is linked with facebook like , when we click it, it published directly to our news feeds http://www.facebook.com/pages/Caution-Wet-Paint-LOL/251653061560367
i'm a newbie

I wrote a blog post on this:
http://dorianroy.com/blog/2010/04/how-to-make-a-friendly-facebook-like-button/