Error 404 for subsequent requests by HTMLs received by AJAX response

Before serving the web page, I am checking some data on user's web browser using javascript. If it is found, then a token will be generated and the same request is made with an additional custom header 'X-Token'.

token = genTokenId(rdCookie('client_id'))
if (found == 1) {
    xmlhttp = new XMLHttpRequest();
    if (xmlhttp) {
        xmlhttp.open(rdCookie('method'), rdCookie('url'), false);
        xmlhttp.setRequestHeader("X-Token", token);
        xmlhttp.onload = function(event)    {
            document.documentElement.innerHTML = xmlhttp.responseText;
            xmlhttp.close();
        }
        xmlhttp.send();        
    }   else    {
        alert("Error! Your browser is not supporting XMLHttpRequest")
    }
}

This code will be delivered for any connection request made by a client. To resume the connection request with generated token this javascript carries "client_id", "url" and "method" in cookies. After generating Token-ID using "client_id", the same request is made using AJAX. Content is delivered successfully, If all web document is available in root directory. If it is in sub-directory, it returns HTTP 200 OK for first time, but return HTTP 404 Not Found for second request under same sub-directory.

For example, request to "/src/feedBackView.php" returns HTTP 200 OK, but subsequent request to "/src/feedBackControl.php" returns HTTP 404 Not Found.

After analyzing I understood, that the url bar is never getting updated during HTTP 302 and 200. Hence, instead of requesting "/src/feedBackControl.php" the browser requests only "feedBackControl.php" Please help me to fix it.