Код:
function processExtImg() {
var imgLink = document.querySelector("input[name='url_to_img']").value;
var url = chatx_server + "imgur_uploader.php";
var xhr = new XMLHttpRequest();
xhr.open("POST", url, true);
xhr.setRequestHeader("Content-Type", "application/json");
xhr.onreadystatechange = function() {
if (xhr.readyState === 4 && xhr.status === 200) {
generateImageTagAndSend(xhr.responseText);
}
};
xhr.send(JSON.stringify({ urlToImg: imgLink }));
}