代码示例:(标识:eg_js_ajax_asyncfalse)
<!DOCTYPE html>
<html>
<body>

<h1>XMLHttpRequest 对象</h1>

<p id="demo">让 AJAX 更改这段文本。</p>

<button type="button" onclick="loadDoc()">更改内容</button>

<script>
function loadDoc() {
  var xhttp = new XMLHttpRequest();
  xhttp.open("GET", "/static/demo/txt/ajax_info.txt", false);
  xhttp.send();
  document.getElementById("demo").innerHTML = xhttp.responseText;
}
</script>

</body>
</html>
运行结果: