Can someone help with the following.

I need a formula that will select the appropriate value based on a range of
dates:
I have 17 dates that are used to determine a proration based on a specific
date entered and I need to match the entered date to a range of dates and
provide the proration as the result.

Cell B1 = 07/05/05

I need the result in B2 to be .80 (I3) since it is greater than 6/30/05 but
less than 07/14/05.

D2 = 01/01/05  D3= 1
E2 = 05/19/05  E3= .96
F2 = 06/02/05  F3= .92
G2 = 06/16/05  G3= .88
H2 = 06/30/05  H3= .84
I2 =  07/14/05 I3 = .80
J2 = 07/28/05 J3= .76
K2 = 08/11/05 K3= .72
L2 = 08/25/05 L3= .68
M2 = 09/08/05 M3 = .64 etc

Thank you in advance for your assistance!