Edit a screen field from script

SOLVED

Hello,

I have a process that sends workflow mail via existing product sites with safety stock, and after it runs, I'd like to set their respective safety stocks to 0. I've marked where I would like to implement this code in my code snippet.

I tried [F:ZITF]SAFSTO = 0, but it did not work.

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......

#--------Filter for sites with Safety Stock > 0--------#

Filter[F:ZITF] Where [F:ZITF]ITMREF = [F:ITM]ITMREF & [F:ZITF]SAFSTO > 0
For[F:ZITF] 

GZITM = [F:ZITF]ITMREF
GZFCY = [F:ZITF]STOFCY
GZSFS = [F:ZITF]SAFSTO

#--------Call workflow--------#

Local Integer TYPEVT : TYPEVT = 1 
Local Char CODEVT : CODEVT = 'ZDS' 
Local Char OPERAT : OPERAT = '' # No rules
Local Char CLEOBJ : CLEOBJ = [F:ITM]ITMREF
Call WORKFLOW(TYPEVT,CODEVT,OPERAT,CLEOBJ) From AWRK

----> Change safety stock [F:ZITF]SAFSTO to 0 in the respective site before moving onto the next one <----

#--------Clear Globals for next site--------#
Raz GZITM, GZFCY, GZSFS

#--------Next site--------#
Next

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Thank you,

Zoey