Fill in the gaps

*(Q) Someone made a file which contained Census Tract#, City Name and Zip Code.

When the city is the same, it was left blank.SO IS THE CASE FOR ZIP CODE.
Here I have a task to rearrange the data.

*(A) posted by Raynald Levesque to SPSSX-L on 2002/02/07.
* The solution is VERY GENERAL, it works (as is) for any number and any mix 
* of numeric and string variables.

DATA LIST LIST / CT(F6.2)  City (A20)  Zip (F5.0).
BEGIN DATA
320.11,'MODJESKA',92676
423.06 'MONARCH BEACH' 92629
423.22
423.23
626.10 'NEWPORT BEACH' 	92660
626.18
627.01
627.17
630.04
630.05
630.07
630.08
630.09
630.10
631.03
627.99 	' '			92661
628.00
630.06	' ' 			92662
628.00	' ' 			92663
629.00
630.05
630.10
634.00
635.00
636.01
636.02
636.03
626.17	' ' 			92625
626.18
627.01
627.02
626.04	'NEWPORT COAST'	92657
626.17
626.18
627.02
762.01	'OLIVE'			92865
762.02
762.98
524.12	'IRVINE'			92602
524.14
525.95
626.04	' ' 			92603
626.17
END DATA.

SET ERRORS=no.
DO IF $CASENUM>1.
DO REPEAT v=ALL.
* The next 2 lines are a nice trick: 
* one the 2 line results in a (non consequential) error 
* but the other gives the correct answer.
IF LEN(RTRIM(v))=0 v=LAG(v).
IF MISSING(v) v=LAG(v).
END REPEAT PRINT.
END IF.
SET ERRORS=yes.
EXECUTE.