xml.setRequestHeader("If-Modified-Since",
jQuery.lastModified[url] || "Thu, 01 Jan 1970 00:00:00 GMT" );
// Set header so the called script knows that it's an XMLHttpRequest
xml.setRequestHeader("X-Requested-With", "XMLHttpRequest");
// Make sure the browser sends the right content length
if ( xml.overrideMimeType )
xml.setRequestHeader("Connection", "close");
// Wait for a response to come back
var onreadystatechange = function(istimeout){
// The transfer is complete and the data is available, or the request timed out
if ( xml && (xml.readyState == 4 || istimeout == "timeout") ) {
requestDone = true;
var status = jQuery.httpSuccess( xml ) && istimeout != "timeout" ?
ifModified && jQuery.httpNotModified( xml, url ) ? "notmodified" : "success" : "error";
// Make sure that the request was successful or notmodified
if ( status != "error" ) {
// Cache Last-Modified header, if ifModified mode.
var modRes;
try {
