请高手解答下面是如何工作的


ht=allt(thisform.txt1.Value)
hs=allt(thisform.txt2.Value)
numval=EVALUATE(thisform.txt3.Value)

IF LEN(ALLTRIM(thisform.txt2.Value))=0 THEN 
   thisform.txt2.SetFocus()

   RETURN 
ENDIF 

IF numval=0 THEN 
   THISFORM.txt3.SETFOCUS()

   RETURN 
ENDIF 

  htlen=LEN(ht) 
  n=1
  DO WHILE n<=htlen
    htd=SUBSTR(ht,n,1)
    fn=VAL(htd+"2")+10
    F=VAL(htd+"2")
    DO WHIL F<fn
      FF=FIEL(F)
      H=1
      DO WHILE H<=LEN(ALLTRIM(hs))
        hsd=VAL(SUBSTR(hs,h,1))
        IF VAL(RIGHT(STR(VAL(SUBSTR(ff,2,1))+VAL(SUBSTR(ff,3,1)),2),1))=hsd THEN 
        REPL &FF WITH &FF+NUMval
        ENDIF
        h=h+1
      enddo
      F=F+1
    ENDD
    n=n+1
  ENDDO 

thisform.txt1.Value=""
thisform.txt2.Value=""
thisform.txt3.Value=""
thisform.txt1.SetFocus()
thisformset.refresh