Vlookup formula =VLOOKUP(A3,DATA2!A1:B19,1,0) does not return correct information.

I am searching for a numeric code from sheet one in sheet 2 to display a separate numeric code back into sheet 1.

What happens is it returns information from a different row, when I put false it says #NA.

I've tried to change the type of format and sorting it but I'm at a loss.

Thanks for your help.
criss