dialog要素

<dialog id="sample">

<button id="close">閉じる</button>

</dialog>



(function () {

    'use strict';



    var dialog = document.getElementById('sample');

    var openBtn = document.getElementById('open');

    var closeBtn = document.getElementById('close');

    var open = function () {

        dialog.showModal();

    };

    var close = function () {

        dialog.close();

    };



    openBtn.addEventListener('click', open);

    closeBtn.addEventListener('click', close);

}());