=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