=IF(ISNA(<formula),"---",<formula)

Just to clarify that the above construct will return: "---"
if <formula evaluates to an #N/A

If you want blanks: "" to be returned instead,
just replace "---" with "" in the construct
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Rgds
Max
xl 97
---
Singapore, GMT+8
xdemechanik
http://savefile.com/projects/236895
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