Create border around white display ad?

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Does anyone know the proper way to add a border around a white display ad? I know I could simply just add a transparent rectangle, but I wasn't sure if there was a proper way to do this. Please see attached image, thanks!

[kglad]

what do you mean by "proper"?  or what's improper about creating, on stage, exactly what you want the user to see?

or, if you're asking about the html5/css to create a div border:  HTML div tag (w3schools.com)