Detect if browser supports createcontextualfragment

Is anyone here familiar with using createcontextualfragment. If so, do you know how to tell if a browser supports that feature?

I just answered an identical thread at siteexperts.com (not sure if that was you...):

http://www.siteexperts.com/forums/viewConverse.asp?d_id=10195

Actually I was asking the question on behalf of someone else. He's the one that made that post at siteexperts.

His original post was at tek-tips:
http://www.tek-tips.com/gviewthread.cfm/lev2/4/lev3/32/pid/216/qid/338686

:)