*! version 1.0.0 PR 10Oct97. STB-43 sg81
program define _fracin /* target_varname varlist_to_check */
* Returns index # of target_varname in varlist_to_check.
local v `1'
local vl "`2'"
local nx: word count `vl'
local k 0
local j 0
while `j'<`nx' {
	local j = `j'+1
	local vj: word `j' of `vl'
	if "`v'"=="`vj'" {
		local k `j'
		local j `nx'
	}
}
global S_1 `k'
if `k'==0 {
    di in red "`v' is not an xvar"
    exit 198
}
end