Hello, hope someone out there can help me out a bit.

This is the problem. I have 2 sheets. One with a summary and calculations
and one sheet with data.
In the summary sheet (Sheet1), I have names which also appear in the data
sheet (Sheet2). However the problem is that in the data sheet the name will
appear several times. I want a function that does the following:
For example:
Calculate the average of column C in Sheet2 for all the rows that contain
the name Charlie.
Anyone have any solution?

Help appreciated. Thanks