SUM of Hours in Month

[roland_c_w]

Ok, Post 2,

I am trying to get the SUM of a col for a Month

The sheet looks a bit like this:

____A_______B______C
1__Date____Hours___Feb
2__1 Jan_____1
3__2 Jan_____1
4__1 Feb_____2
5__2 Feb_____3
6__2 Mar_____1
7__3 Mar_____2

the Function i'm trying to get working is:
=SUM(LOOKUP(MONTH(C1),MONTH(A:A),B:B))

To my mind this should return a value of 5,
But all i get is: #NUM!



Please help!