How to convert a youtube video url to the iframe embed code?

<script type="text/javascript">
function Player(){
var ytID=document.getElementById("yt-url").value.replace(/(.*?)\?v=/,"");
document.getElementById("player").innerHTML="<iframe width=\"560\" height=\"315\" src=\"https://www.youtube.com/embed/"+ytID+"\" frameborder=\"0\" allowfullscreen></iframe>";
}
</script>
<input placeholder="https://www.youtube.com/watch?v=jh1smoiDcWs" onkeyup="Player()" onchange="Player()" type="text" id="yt-url">
<div id="player"></div>

Result: