IsVBSReady Function:

The IsVBSReady function determines if the client browser is capable of using client-side VBScript. Returns True if the browser supports VBScript or False if it does not. If the system cannot determine the VBScript readiness of a browser, IsVBSReady returns Null.

boolean = IsVBSReady()
Example Usage:
dim a
a = IsVBSReady
if a then
	 ' browser supports client-side vbscript
elseif not a then
	 ' browser doesn't support client-side vbscript
elseif IsNull( a ) then
	 ' browser vbscript support is unknown
end if
ASP Source Code:
Private Function IsVBSReady()
	dim bc
	Set bc = Server.CreateObject("MSWC.BrowserType")
	IsVBSReady = bc.vbscript
	if Lcase(IsVBSReady) = "unknown" then _
		IsVBSReady = Null
	Set bc = Nothing
End Function