The answers provided to my previous post made it possible for me to obtain
the results I needed, but now I'd like to create a custom formula so I don't
have to type the whole thing out every time. In Microsoft Visual Basic I've
created a module that reads like this:

Function Commission(sales)
If sales < 150000 Then
Commission = sales * 0.0125
End If
If 150000 < sales < 200000 Then
Commission = sales * 0.0175
End If
If sales 200000 Then
Commission = sales * 0.02
End If
End Function

But when I try to insert the formula into my worksheet, it says that it
takes no argument. Help?

Thanks,
Sarah