This is the standard JQuery Mobile distribution (1.0b1).

Note that in the context of widgets there are certain practices to consider in that default "dialog.close" and "window.back" behaviour
has unpredictable results on a more complex page with iFrames in different browsers. You should wherever possible use either links
or scripts that directly invoke a page transition rather than rely on browser functions in these cases. 

For more information see https://github.com/jquery/jquery-mobile/issues/560

Note that JQuery Mobile will no longer automatically create "Back" buttons for pages, and instead encourages developers to
create a "home" link/button/image/logo or similar in the page header, as is typical of web applications more generally.