totalling cells

[Davycc]

Guys silly question time again.

In the example attached there is a figure entered each week in col J. I need the totals to add up in col C for each name every time there is a new figure added. At the present the total for Dave would be 14 and if in week 5 was entered for Dave the total in col C for dave would change to 19.

As usual any help would be much appreciated.