Register Dialog Polyfill

app.js

(function() {

    let openDialog = document.getElementById('openDialog');
    let openModalDialog = document.getElementById('openModalDialog');
    let dialogWindow = document.getElementById('dialogWindow');

    dialogPolyfill.registerDialog(dialogWindow);

    openDialog.addEventListener('click', () => {
      dialogWindow.show();
    })

    openModalDialog.addEventListener('click', () => {
      dialogWindow.showModal();
    })
  })();