A simple task that I just can't get to work...

I have a simmple table in which I enter a number in a cell. I then
want to LOOKUP this number and if it matches what I am looking for I
want to return "1" if not return "0"

eg

A B
636 1
658 0
659 0
624 1
632 0

using the above table I want to look up the numbers in column A in a
seperate table and if it in the lookup table, return "1" if not "0"
the lookup table has

624 1
636 1
637 1
660 1

I got Vlookup to work but if the number is not in my lookup table I
get an #N/A returned which I don't want


Any suggestions would be helpfull or a better idea I'd br gratefull

G..