*! version 1.0.0  10/28/93                      STB16: zz3
program define stb_idx /* insert length */
	version 3.1
	local insert =lower("`1'")
	local l `2'
	local i=1
	qui drop _all
	qui set obs 1
	qui gen str6 stb = "0"
	while (1) { 
		capture stb_find stb`i'
		if _rc { 
			if `i'>15 { 
				qui drop if stb=="0"
				cap drop file
				exit 
			}
		}
		else {
			quietly {
				append using $S_1
				if `l'==-3 {
					keep if index(lower(file),"`insert'") /*
						*/ | stb=="0"
					keep stb insert ttl author file
					sort stb insert
					quietly by stb insert: keep if _n==1
				}
				else {
					keep stb insert ttl author 
					sort stb insert 
					quietly by stb insert: keep if _n==1
					if `l'==-1 {
						keep if /*
					*/ index(lower(ttl),"`insert'") | /*
						*/ stb=="0"
					}
					else if `l'==-2 {
						keep if /*
					*/ index(lower(author),"`insert'") | /*
						*/ stb=="0"
					}
					else keep if /*
					*/ substr(lower(insert),1,`l')== /*
						*/ substr("`insert'",1,`l') | /*
						*/ stb=="0"
				}
			}
		}
		local i=`i'+1
	}
	/*NOTREACHED*/
end