Ah, HA! Within the function, I am assigning a different variable to the window.open, but I am not returning it. Thanks, Andrew! I'll give that a shot and report back.
If anyone knows of a website that can offer ColdFusion help that isn't controlled by neurotic, pedantic jerks* (stackoverflow.com), please PM me with a link.
* The neurotic, pedantic jerks are not the owners; just the people who are in control of the "popularity contest".