如何發送一個XMLHttpRequest的檢索的特定部分HTML標題資料。
<html>
<head>
<script type="text/javascript">
var xmlhttp;
function loadXMLDoc(url)
{
xmlhttp=null;
if (window.XMLHttpRequest)
{// all modern browsers
xmlhttp=new XMLHttpRequest();
}
else if (window.ActiveXObject)
{// for IE5, IE6
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
if (xmlhttp!=null)
{
xmlhttp.onreadystatechange=state_Change;
xmlhttp.open("GET",url,true);
xmlhttp.send(null);
}
else
{
alert("Your browser does not support XMLHTTP.");
}
}
function state_Change()
{
if (xmlhttp.readyState==4)
{// 4 = "loaded"
if (xmlhttp.status==200)
{// 200 = "OK"
document.getElementById('p1').innerHTML="This file was last modified on: " + xmlhttp.getResponseHeader('Last-Modified');
}
else
{
alert("Problem retrieving data:" + xmlhttp.statusText);
}
}
}
</script>
</head>
<body>
<p id="p1">
該getResponseHeader ( )函數返回一個標題的資源。標題包含的檔案資訊,如長度,伺服器類型,內容類型,日期修改等.</p>
<button onclick="loadXMLDoc('test_xmlhttp.txt')">Get "Last-Modified"</button>
</body>
</html>