What Does jQuery UI Recommend for Rounded Corners on FF2/IE7 ?

What Does jQuery UI Recommend for Rounded Corners on FF2/IE7 ?


I notice that ThemeRoller (http://ui.jquery.com/
themeroller#themeGallery) has rounded corners even on browsers that
don't support the CSS3 border-radius property, like Firefox 2. What do
I need to download or include in my jQuery UI custom install, so that
my site can do the same thing?
Thanks very much in advance to all for any info.
-Vik