viewport widget

I want to use the view port widget to include a property listing in my website but cant figure for the life of me how to do it, ive read the documentation i can find, but am not sure how i reference the external script.

This has been doing my head in for a while so as much help as poss appreciated

You need to create a TV, then apply a widget to it.

For reference:
Creating a Template Variable (TV)
http://modxcms.com/creating-a-template-variable.html
A View Port Widget
http://modxcms.com/view-port-widget.html

k i get that but i guess i am nhot sure how to creat the tv, or how i reference it in the widget, and what imput type it would be (URL)?