dialog-polyfill.js is a polyfill for dialog and form method="dialog". Dialog is an element for a popup box in a web page, including a modal option that will make the rest of the page inert during use. This could be useful to block a user's interaction until they give you a response, or to confirm an action. See the HTML spec. This polyfill works on modern versions of all major browsers. It also supports IE9 and above. It can work when used inside Shadow DOM, but it's not recommended. ...