If you're looking for prior art (Score 1)

Some unfortunate guy suggested IsNot publicly in one of Microsofts usenet forums way before 2003:

http://groups.google.com/groups?q=IsNot+VB7&hl=en& lr=&selm=86a0qh%243th%241%40ssauraab-i-1.productio n.compuserve.com&rnum=1

(yep, that was me and I'm sorry I did. :( )