document.getElementById("loginsubmit").addEventListener("click", function () {
    var xhttp = new XMLHttpRequest();
    xhttp.onreadystatechange = function () {
        if (this.readyState == 4 && this.status == 200) {
            alert("logged in");
            console.log("dziala");
        } else if (this.readyState == 4) {
            alert("something not work :( " + this.status);
            console.log("nie dziala");
        }
    }
    xhttp.open("POST", "https://dragonmaster.pl/inz/user/login");
    xhttp.send('{"username":"' + document.getElementById("loginusername").value + '","password":"' + document.getElementById("loginpassword").value + '"}');
});

function submit() {
    ("form").submit(function () { return false; })
}