console
var xmlhttp;
function loadXMLDoc(url)
{
xmlhttp=null;
if (window.XMLHttpRequest)
{
xmlhttp=new XMLHttpRequest();
}
else if (window.ActiveXObject)
{
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)
{
if (xmlhttp.status==200)
{
document.getElementById('p1').innerHTML=xmlhttp.getAllResponseHeaders();
}
else
{
alert("Problem retrieving data:" + xmlhttp.statusText);
}
}
}
<p id="p1"> The getAllResponseHeaders() function returns the headers of a resource. The headers contain file information like length, server-type, content-type, date-modified, etc.</p>
<button onclick="loadXMLDoc('/example/ajax/test_xmlhttp.txt')">Get Headers</button>