Testing for an Excel wookbook being open or not

How do I test if an Excel workbook is open or not?

Perhaps something like this

IsWorkbookOpen("Workbook1") -- false
IsWorkbookOpen("Workbook1.xls") -- true


on IsWorkbookOpen(workbookName)
	tell application "Microsoft Excel"
		return (0 < (count of ((every workbook whose name = workbookName) as list)))
	end tell
end IsWorkbookOpen

Thanks man!!

Works like a charm.

( I dabble from time to time in programing, REALbasic, AS, VB, VBA, ReXX, C/C++, asm, etc, with the little I do, keeping the sublties of each is tough.)