function loadScript(url){ let xhr = new XMLHttpRequest() xhr.open('get',url,true) xhr.onreadystatechange = function(){ if(xhr.readyState == 4){ if(xhr.status >= 200 && xhr.status <= 300 || xhr.status == 304){ let script = document.createElement('script') script.type = 'text/javascript' script.text = xhr.responseText document.body.appendChild(script) } } } xhr.send(null) }