Help With Crystal isnull Syntax

HELLO...

Crystal is driving me nuts :-)

I'm trying to use a formula...something like the following...where I'm testing if the *PREVIOUS* record is a null...for Suppression purposes:

isnull(Previous({@1A_Item+Locn}))

BUT...every time I attempt this...Crystal is barking with that silly "...A field is required here..." error message.  What am I doing wrong?  I've tried this numerous different ways.  I *KNOW* that the result of that Calculated field...*IS*...indeed...a NULL value (in certain circumstances, based on the underlying data)...and that's both fine and accurate.  I simply want to SUPRESS...based on this condition...and, yes, the *PREVIOUS* function is important here.

PLEASE HELP!  I'm stuck.  As always, I appreciate anyone's assistance :-)...Thanks!...Mark
datatechcorpAsked:
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mlmccCommented:
IsNull and Previous are for database fields only.  They will not work on formulas

There is a PreviousIsNull test you can use if that is a database field. That will test the previous database field to see if it was NULL.

mlmcc

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datatechcorpAuthor Commented:
***  OMG...THANK YOU!!!  ***  This worked...and I *fully* appreciate it!...Mark
mlmccCommented:
FYI there is also a NextIsNull function if you ever need it.

mlmcc
datatechcorpAuthor Commented:
Great to know!  Thanks MLMCC...you're the best! :-)
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