// TODO:
    var
        username = document.getElementById('username').value,
        pwd1 = document.getElementById('password').value,
        pwd2 = document.getElementById('password-2').value,
        MYAPP = {},
        reUsername = /^[\w\d]{3,10}$/,
        rePwd = /^[\w\d]{6,20}$/;

    MYAPP.ret = true;

    if (reUsername.exec(username) === null) {
        alert('Invalid Username!');
        MYAPP.ret = false;
    }
    if ((rePwd.exec(pwd1) === null) || (rePwd.exec(pwd2) === null)) {
        alert('Invalid Password!');
        MYAPP.ret = false;
    }
    if (pwd1 != pwd2) {
        alert('Two password are not same!');
        MYAPP.ret = false;
    }

    return MYAPP.ret;
}