Thanks for the reply.
The URL for my PUT request is actually doing some server-side logic and then redirecting to a new URL.
I tried the above code, and it looks like it executes an AJAX request.. i.e. asynchronous,.. so it's not changing the web page.
I guess what I'm looking for is just a straight synchronous request to a URL using a method of 'PUT', so something like this:
window.location.href = (some URL);
..but that would execute it with a method of 'PUT' instead of 'GET'.