Looks like IsBlank() does not work for numeric and logical fields. Am I missing something?

CLEAR
CLOSE TABLES all

create TABLE c:\junk (fldBlob W, fldChar c(10), flddate D, flddt T, ;
	fldg G, fldlogic L NULL,;
	fldM M, fldN N(6,1) NULL,fldfloat F(6,1) NULL, fldVar Q)

APPEND blank

COUNT FOR ISBLANK(fldLogic) OR ISBLANK(fldN) TO ln
?ln   && 1
SELECT * FROM c:\junk WHERE ISBLANK(fldLogic) OR ISBLANK(fldN) INTO CURSOR tmpcurs1
?_tally   && 0
sele;
	fldLogic, ISBLANK(fldLogic) _fldLogic, isb(fldLogic) _fldLogic1,;
	fldN, ISBLANK(fldN) _fldN, ISB(fldN) _fldN1,;
	fldFloat, ISBLANK(fldfloat) _fldFloat, ISB(fldfloat) _fldFloat1;
	from c:\junk;
	into curs tmpcrs2

?ISBLANK(fldLogic), _fldLogic
?ISBLANK(fldN), _fldN
?ISBLANK(fldfloat), _fldFloat


*---------------------------
PROCEDURE isb
LPARAMETERS pField
RETURN ISBLANK(pField)