I have an excel workbook with several sheets. On one sheet I have "details"
with a column identifying "cost centers". In another sheet I want to show the
sums of the different cost centers (a summary of the details). Is there a
function whereby I can have all the detailed items summed by cost center
identification number from the column in the details sheet reflect
automatically in the summary sheet? Maybe a simplified example:

detail sheet:
cc amt
100 5.00
100 6.00
101 1.00

summary sheet:
cc amt
100 11.00
101 1.00

Of course, the detail sheet has hundreds of cost centers and many more
individual entries. I just want some sort of conditional lookup that will
find and sum all like cost center entries.