*! 3.0.0 NJC 25 Sept 2003
program npresent, byable(recall)
	version 8.0
	syntax [varlist] [if] [in] [, * ]

	marksample touse, novarlist
	qui count if `touse'
	if r(N) == 0 error 2000

	nmissing `varlist' if `touse', `options' present
end