Opens a modal window that displays the specified web page.
A modal window displays the page specified by the url property over
a current page. Unlike a lightbox, which
is opened by calling openLightbox() method, a window
opened by openModal() isn't part of a site's structure.
Only 1 modal window can be open at any given time. Therefore, opening a modal window closes an already open modal window if there is one.
Note: The specified url must be an HTTPS URL.
The URL of the page to show in the modal window.
Modal window options.