*! savin -- save a subset of the current data set       (dm23: STB-22)
*! version 1.0     David Mabb     October 12, 1994
program define savin
version 3.1
quietly {
        local varlist "opt ex"
        local if "opt pre"
	local in "opt pre"
        local using "req nopre"
        local options "noLabel REPLACE"
        parse "`*'"
        preserve
        if "`if'`in'"!="" { keep `if' `in' }
        keep `varlist'
}
        save `using', `replace'
end