Youtube loading effect

<!DOCTYPE>
<html>
<header>
<style>
#progress {
	position: fixed;
	z-index: 2147483647;
	top: 0;
	left: -6px;
	width: 1%;
	height: 2px;
	background: #0088CC;
	-moz-border-radius: 1px;
	-webkit-border-radius: 1px;
	border-radius: 1px;
	-moz-transition: width 500ms ease-out,opacity 400ms linear;
	-ms-transition: width 500ms ease-out,opacity 400ms linear;
	-o-transition: width 500ms ease-out,opacity 400ms linear;
	-webkit-transition: width 500ms ease-out,opacity 400ms linear;
	transition: width 500ms ease-out,opacity 400ms linear;
}
#progress dd, #progress dt {
	position: absolute;
	top: 0;
	height: 2px;
	-moz-box-shadow: #0088CC 1px 0 6px 1px;
	-ms-box-shadow: #0088CC 1px 0 6px 1px;
	-webkit-box-shadow: #0088CC 1px 0 6px 1px;
	box-shadow: #0088CC 1px 0 6px 1px;
	-moz-border-radius: 100%;
	-webkit-border-radius: 100%;
	border-radius: 100%;
}

#progress dt {
	opacity: .6;
	width: 180px;
	right: -80px;
	clip: rect(-6px,90px,14px,-6px);
}

#progress dd {
	opacity: .6;
	width: 20px;
	right: 0;
	clip: rect(-6px,22px,14px,10px);
}
</style>
<script>
  function show () {
            document.body.innerHTML+="<div id=\"progress\"><dt></dt><dd></dd></div>";
            var pr=document.querySelector("#progress");
            setTimeout(function(){
                pr.style.width="60%";
                },300);

            setTimeout(function(){
                pr.style.width="101%";
                },800);


            setTimeout(function(){
                pr.parentNode.removeChild(pr);
                },1600);
            return false;
          }
$(document).ajaxStart(function() {
    //only add progress bar if added yet.
    if ($("#progress").length === 0) {
        $("body").append($("<div><dt/><dd/></div>").attr("id", "progress"));
        $("#progress").width((50 + Math.random() * 30) + "%");
    }
});

$(document).ajaxComplete(function() {
    //End loading animation
    $("#progress").width("101%").delay(200).fadeOut(400, function() {
        $(this).remove();
    });
});
</script>
</header>
<body>
<div>
	<a onclick='show();' href='#' class='btn'>Show Demo</a>
</div>
</body>
</html>