jQuery UI dialog allows you to display any content in a popup box, given the content is already present somewhere within page (e.g., in the DOM tree). However, you may want to display content in a popup box that has to be fetched from the server.

Now, here is how you can display a URL into a modal window (in-page popup) with jQuery UI dialog. Do note that this only works for pages hosted on the same domain because of same origin policy