sum of products of a search for a value

Hi,
I'm trying to search column A for a value, say 1 & then return a sum of the products in column B that are in the same row of the value 1

I can't seem to attach anything yet, so


A B
1 10
1 15
1 20
5 1
6 10


Cell E4 has the value of 1 - I need to search column A for the value of E4 & return the sum of the products in column B into the cell E5 e.g. sum = 45 in the example

I might be over simplifying, but does this cover it?

Put this is E5
=SUMIF(B2:B6,E4,C2:C6)

E4 has a 1 in it and the result is 45, because it looks down column A and every time it finds a 1 it adds up what's adjacent to the 1 in column B.

Entering 6 in cell E4 would return 10.

That works great.

Thank you so much for the speedy answer, it's very much appreciated

Not a problem, sumif is a very useful formula - one for the kitbag.