// read text from URL location var request = new XMLHttpRequest(); request.open('GET', 'https://jhodges.co.uk/dev/error.txt', true); request.send(null); request.onreadystatechange = function () { if (request.readyState === 4 && request.status === 200) { var type = request.getResponseHeader('Content-Type'); if (type.indexOf("text") !== 1) { str=request.responseText.trim(); if(str){ alert(str); } } } }