An efficient way to Copying values in subsequent records - SAS -

i have dataset grouped category variables in source data. example:

bar  | foo1      | foo2      | foo3 bar2 | foo4      | foo5      | foo6 

after import source data, above result in first variable (parent) being populated on record 1 not #2 , #3. copy parent variable's value record 2 , 3. output more this:

bar  | foo1 bar  | foo2 bar  | foo3  bar2 | foo4 bar2 | foo5 bar2 | foo6  

i tried using "lag" function, doesn't seem working. here code:

if parent ~= "" do;    parent = parent; end; else do;    parent = lag(parent); end; 

you can retain non-missing value , apply missing values, e.g.

 data want ;   set have ;    length last $10. ;   retain last '' ;    if not missing(parent) last = parent ;   else parent = last ;    drop last ; run ;