Lookup with if Statement

Hi,

I have two tables called Table1 and Table2. Each table has columns with Unit numbers. I want to add a column to Table2 that will look into Table1 to see if the Table2 Unit is contained in Table1 then return true or false.

This formula:

= Table.AddColumn(#"Changed Type", "Custom", each if [Unit] = Table2[UnitCode] then true else false) just returns False for each line. What formula can i write to do a if lookup from another table? Thanks.