function api_ajax_request(method, url, onSuccess, onFail, sendData) {
    var xmlhttp = new XMLHttpRequest();
    // csrftoken is set globally
    xmlhttp.onreadystatechange = function() {
        if (xmlhttp.readyState == XMLHttpRequest.DONE) {
            if (xmlhttp.status == 200) {
                //console.log("Success:"+xmlhttp.responseText);
                onSuccess(method, url, JSON.parse(xmlhttp.responseText));
            } else {
                onFail(method, url, xmlhttp.status, xmlhttp.responseText);
            }
        }
    }

    xmlhttp.open(method, url);
    xmlhttp.setRequestHeader('X-CSRFToken', csrftoken);
    if (sendData === null || typeof sendData === 'undefined') {
        xmlhttp.send();
    } else {
        xmlhttp.send(JSON.stringify(sendData));
    }
}

function api_ajax_request_without_send(method, url, onSuccess, onFail) {
    return api_ajax_request(method, url, onSuccess, onFail, null);
}

function api_search_user(search, onSuccess, onFail) {
    return api_ajax_request_without_send('GET', api_urls_v1['user-list']+`?search=${encodeURIComponent(search)}`, function(method, url, json) {onSuccess(json);}, onFail);
}