How do I reference VLookup returned Cells that have "#N/A

[Guest]

I have run a simple VLookup comparing part numbers in one sheet with part
numbers in a nother sheet to see if there are matching part#'s. In the event
there is a match, the VLookup lists the matching #'s, but when there is not a
match, it creates a #N/A in the output cell.

Here is an example of a formula I'm using:
=VLOOKUP('315'!B5,'345'!$B$5:$C$8507,1,FALSE)

When the formula returns a "#N/A", I would like to list the partnumber from
'315'!B5 on a seperate sheet.

Any ideas? I've spent almost 4 hours going through various "if"
combinations, and anytime I reference one of these "#N/A" cells, everything
comes out "#N/A" regardless of the formula.

 

[Niek Otten]

=IF(ISNA(YourFormula),OtherFormula,YourFormula)