Send AJAX Request via JS Function

SendAjaxRequest.MD

function ajax_request() {
    var xhttp = new XMLHttpRequest();
    xhttp.onreadystatechange = function() {
        if (this.readyState == [READY_STATE] && this.status == [HTTP_RESPONSE_CODE]) {
            // do something
        }
    };
    xhttp.open("GET", [REQUEST_PATH], true);
    xhttp.send();
}

Status of the XMLHttpRequest

Changes from 0 to 4:

0: request not initialized

1: server connection established

2: request received

3: processing request

4: request finished and response is ready

HTTP Response Codes:

200: "OK"

404: "Page not found"