vba excel - if cycle

I have 2 columns with USD amounts of payments I need to compare. Data is from two different sources but they should match. Every month there is different number of payments so I dont know if next time there will be 20 or 30 of them. So I need to compare these 2 columens. What I want to do is using if function

If [n3] = [u3] Then
    [q3] = "yes"
Else
    [q3] = "no"
End If

and I dont know how to use cycles to do this with every payment. Can you help me please. Thank you