Automatically adding up cells with corresponding row names

Hi guys,

I have the following problem: I want to add up cells that have a corresponding row name. Because I have a data file that consists of more than 13.000 rows it would save me alot of time if Excel can do this automatically. I presume it's possible but don't know how to do it.

In the attachment you can see what I mean. The numbers in the A column are customer numbers. I want to know what's the total amount spent by each customer, just like the red figures in the c column.

If I would use SPSS for example to create a bar chart of the sum of the amounts spent per customer I would see it graphically, but I need the figures as figures and not as bars!

Who is going to make my day and show me the solution. Thanks in advance for your attention!

thanks for your response!!

this is only not what I mean. to make it simple, I want to have the subtotals per customer number of their revenues

in excel97 there is a function called subtotal which works perfect, I'm going to check at home if i cans till use this function in excel 2007

thanks again i will report my findinggs!