Question : numberVar in isNull function

I defined an array with table fields:
Local numberVar array H := MakeArray ({t1.fld1}, {t1.fld2},... ,{t1.fld12});
and I need to loop it until a null is found.
A msgBox: "A field is required here." pops for the line:
if isNull(H[i]) then exit for;

How to check if a numberVar is null?

Answer : numberVar in isNull function

Happy New year!!!
Please try this...

Numbervar i;
  for  i:= 1 to 12-1  do
  (
   If Length(Trim(H[i])) = 0 Then
       Exit For;
  )