My Mind is Nested... ~>_<~

The Coding below work right on:
Pre-Condition: AChecks(9999) is an Array carry simple .T. or .F.
Post-Condition: CTNLIST show out the Simplest form on number list, Carry the Carton# of used.

How to make another CTNMISS carry the .F. List, which mean missing Carton#

For example,

ITEM# CTN_NOS
A111 003,005-008
B222 004,007-012
C333 014,016,020-030

Result:
CTNLIST: 003-014,016,020-030
[b]How to modify the below coding to give this Expected CTNMISS:
013,015,017-019[/b]

Another String Carry Duplicate Carton# is simply done as similiar copy of below For-loop.

I have tried a whole day on adding new code, but still fail of my expect result...
Thus, post the correct starting code for you on helping me...

Thank you.

[pre]
* STD: AChecks()
CTNLIST = "" && CARRY REAL CTN_NOS, CTNCHECK
CTNMISS = "" && CARRY CTN MISSED
CTNLEN = 0 && LEN OF CTN MSG SHOW
LASTTAKE = 0 && LAST CTN IS .T. TAKEN
LASTSKIP = 0 && LAST CTN IS .F. SKIP
LASTCTN = 0 && LAST CTN# OF 003-00#
LASTMISS = 0 && LAST MISS# OF 004-00#
FOR IK = 9999 TO 1 STEP -1
IF ACHECKS(IK) = .F.
IF EMPTY(CTNLIST) && EMPTY TAIL
LOOP
ENDIF
* FEED HEAD CARTON#
IF (LASTSKIP = IK + 1) .OR. ( LASTCTN = IK +1) && LAST .F. (SKIP CASE), UNIQUE CTN
* DO NOTHING
ELSE
CTNLIST = PADL(IK+1, CTNLEN, '0') + '-' + ALLTRIM(CTNLIST)
ENDIF
LASTSKIP = IK
ELSE
IF EMPTY(CTNLEN) && 1ST .T.
CTNLEN = CEILING( LOG(IK+1)/LOG(10) ) && BETWEEN 10^X
CTNLIST = PADL(IK, CTNLEN, '0') && SHOULD FIT
LASTTAKE = IK
LASTCTN = IK
LOOP
ENDIF
IF LASTTAKE = IK + 1 && LAST .T.
IF IK = 1
CTNLIST = PADL(1, CTNLEN, '0') + '-' + CTNLIST
ENDIF
ELSE
CTNLIST = PADL(IK, CTNLEN, '0') + ',' + CTNLIST
LASTCTN = IK
ENDIF
LASTTAKE = IK
ENDIF
ENDFOR
[/pre]