New to all this so any help would be really appreciated. (Using Office 2003)

I have 2 worksheets and need a formula (possibly index/match) to add up
total course hours in Worksheet 2 where the Course Number in Column A matches
the course number in column B.

Worksheet 1
Column A Column B
Course Number Course Hours
1 20
1 25
2 30
2 35

Worksheet 2
Column A Column B
Course Number Total Course Hours
1 ?
2 ?


As I say any help would be greatly appreciated.

Many thanks

Adrian