Index/Match returning unwanted data

[scadaman29325]

I'm getting more than I wanted. If there is no match, I would like nothing returned.

Using this from Office support:
=INDEX(array or reference, MATCH(lookup_value,lookup_array,[match_type])


I think this is right, it gives me the value I want. The function is in cell M18. I want to copy it to M2 to M11122.
=INDEX(MetNotes!$C$1:$C$625,MATCH(A17,$A$1:$A$11122,0))
=Index(Table to be referenced for the result I want,MATCH(item to be looked up, table of items to be looked up, exact match))

The problem is that when I copy down this function, I get a value and I should not, because there is no match. I'm getting the same value as the preceding cell.
This is what I have in M18
=INDEX(MetNotes!$C$1:$C$625,MATCH(A18,$A$1:$A$11122,0))
There should be no match for the data in A18 and I want M18 to be blank.

Any help would be APPRECIATED! TIA, Phil.

 

[scadaman29325]

WRONG, please disregard, need to figure something out.