You have to separate the OR conditions.

If ISNA is TRUE then the separate VLOOKUP will return #N/A causing the OR to
fail.

=IF(ISNA(VLOOKUP(A4,Sat!$A$16:$J$377,9,0)),"",IF(V LOOKUP(A4,Sat!$A$16:$J$377,9,0)=0,"",VLOOKUP(A4,Sa t!$A$16:$J$377,9,0)))

--
Biff
Microsoft Excel MVP


"Bernard Liengme" wrote in message
...
=IF(OR(ISNA(VLOOKUP(A4,Sat!$A$16:$J$377,9,FALSE)),
VLOOKUP(A4,Sat!$A$16:$J$377,9,FALSE=0,"",VLOOKUP(A 4,Sat!$A$16:$J$377,9,FALSE))
best wishes
--
Bernard Liengme
http://people.stfx.ca/bliengme
Microsoft Excel MVP

"Steve" wrote in message
...
This formula works if the data is present, however, I'm getting #N/A if
the
lookup cell (A4) doesn't exist, which it may not on some days.

=IF(VLOOKUP(A4,Sat!$A$16:$J$377,9,FALSE)0,VLOOKUP (A4,Sat!$A$16:$J$377,9,FALSE),"")

Can this formula be modified to also produce "" if the data representing
A4
does not exist ?

Thanks,

Steve