print isNumeric("123")
print isNumeric("1ab")

' ------------------------
' Numeric Check
' 0 = bad
' 1 = good
' ------------------------
FUNCTION isNumeric(f$)
isNumeric = 1
f$	= trim$(f$)
if left$(f$,1) = "-" or left$(f$,1) = "+" then f$ = mid$(f$,2)
for i = 1 to len(f$)
        d$ = mid$(f$,i,1)
	if d$ = "," then goto [nxtDigit]
	if d$ = "." then
                if dot$ = "." then isNumeric = 0
		dot$	= "."
		goto [nxtDigit]
	end if
       if (d$ < "0") or (d$ > "9") then isNumeric = 0	
[nxtDigit]
next i
END FUNCTION