var html = "";
document.body.insertAdjacentHTML('beforeend', html);
let chatbutton = document.getElementById('shop4d-chat');
chatbutton.onclick = function(){
    window.open('https://shop4d.com/common/chat.php?usertype=websitechat&cid=OQ,,&meta='+currentUrl,'s4dchat',"popup,left=100,top=100,width=420,height=620")
}