empty field with FldGetTextPtr()

[pete moss]

if i execute this line of code:

FldGetTextPtr(FrmGetObjectPtr(frm, FrmGetObjectIndex(frm, objectID)));

i get the text of a field in my form.  i then convert it to an integer
using StrAToI().  now if i do this on an empty field, the resulting Long
turns out to be 0 (zero).  i want to try to catch an empty field for an
error.  what does an empty field return?  i have tried 0 (zero), NULL,
and "" (empty string), but it seems to be none of these.  anyone know
what i should test for?

:P