function login() {
    let nicknameF = document.getElementById("nickname"); // fetch fields
    let pwF = document.getElementById("password");
    let nickname = nicknameF.value; // extract values
    let pw = pwF.value;

    let loginReq = {
        action: "login",
        nickname: nickname,
        password: pw
    };

    request(loginReq).then(resp => {
        if (resp === "OK") {
            location.href = "main.php"
        }
    });
}

const FRAME_RELATIVE_LOCATION = "";

function open_in_content_frame(url, isFrame = true) {
    document.getElementById("content_frame").src = (isFrame ? FRAME_RELATIVE_LOCATION : "") + url;
}

var USERDATA = {};
function load_userdata() {
    let req = {action: "get_user_info"};
    request(req).then(resp => {
        USERDATA = JSON.parse(resp);
    });
}

load_userdata();

// ---------------