Interacting with the browser's chrome to close the active window.

[Rhed]

I'm using CubicTest to write Watir scripts for testing software as it
is developed. On one of the pages, there is a link which opens the new
window and displays a pdf. The only way to close the new window is
through the conventions of the browser chrome.

Is it possible to close a pop-up window using the browser's chrome?

Thanks for your help.