Here's what I've got:

Select Case Maxdpd
Case Is <= 39
dpdval = R15
Case Is <= 59 39
dpdval = R2
Case Is <= 89 59
dpdval = R3
Case Is 89
dpdval = R4
End Select

As you can probably guess, this is not working. dpdval is returning 0
for every case except the <= 39. How do i fix this?