var last_id = 0;

function searchDirectory() {
    var input = document.getElementById("search").value;
    last_id++;
    var request_id = last_id;

    var data = new FormData();
    data.append("query", input);

    var xhttp = new XMLHttpRequest();
    xhttp.onreadystatechange = function() {
        if (request_id != last_id) return;

        if (this.readyState == 4 && this.status == 200) {
            var result_div = document.getElementById("search-results");
            result_div.innerHTML = xhttp.responseText;
        }
    };
    xhttp.open("POST", "/directory/search", true);
    xhttp.send(data);
}