var tag=document.createElement('script');
tag.src="https://www.youtube.com/iframe_api";
var firstScriptTag=document.getElementsByTagName('script')[0];
firstScriptTag.parentNode.insertBefore(tag, firstScriptTag);
var player;
function onYouTubePlayerAPIReady(event){
var iframe_player=document.querySelectorAll(".iframe_player");
for (var i=0; i < iframe_player.length; i++){
var image=new Image();
image.src="https://i3.ytimg.com/vi/"+ iframe_player[i].dataset.embed +"/hqdefault.jpg";
image.alt="click to play the video";
image.addEventListener("load", function(){
iframe_player[ i ].appendChild(image);
}(i) );
iframe_player[i].addEventListener("click", function(){
player=new YT.Player(this.id, {
height: '',
width: '',
videoId: this.dataset.embed,
events: {
'onReady': onPlayerReady
}});
function onPlayerReady(event){
event.target.playVideo();
}
this.innerHTML="";
});
}};