I am looking for a way to add a button to a form to browse for a file to show in the webviewer and automatically add the address location?

Unfortunately FileMaker has not given us a plain "choose file" script step, which would do nothing with the file, just let us choose it. Maybe that seems odd from FileMaker's point of view. But it would often be useful for developers. Most other "scripting" environments have it.

But what you could easily do is use Insert File, [x] As reference only, into a container field. That would get you the full FileMaker syntax file path, as the last value of GetAsText ( container ).

You'd then need to convert that path with a calculation into one that would work with Web Viewer. Open a file with your web browser to see what that would look like, then tweak to match. Remember to make it URL syntax, ie., %20 for spaces, etc..