Okay, thanks for working with me on this. I wasn't seeing that text because: Firefox prevented this page from automatically redirecting to another page. If I "

Okay, thanks for working with me on this. I wasn't seeing that text because: Firefox prevented this page from automatically redirecting to another page. If I "allow" that redirection, then it shows what's in your image. And it properly refines the results without needing help from JavaScript. Firefox is probably doing that because under Preferences -> Advanced I have checked the box: Warn me when websites try to redirect or reload the page. I just tried a virgin Firefox installation and that box is not checked by default. I don't know if it was the default in older versions, or if I flipped it myself.