You are on the right track.

Use this as criteria for an update query --
Like "*/*"
Use this as the update ---
Left([Field19],InStr([Field19],"/")-1)


"MB" wrote:

I have a table of about 25 fields. Field19 is a column of Last Names, but
some of the records have extra text in it. This extra text begins with a
"/". I need to do an update or make table query that would clean up the Last
Names by removing everything after the /. This is what I tried to come up
with myself:

Expr1:
IIf(InStr([Field19],"/")1,Left([Field19],InStr([Field19],"/")-1),([Field19]))

but it give me an "Invalid Argument" error.

Please help.