Hello all,
   I am working on a spreadsheet and I need to figure out how to
define a unique string.  In my sheet, column 1 is a list of classes
offered at a school.  So column 1 contains strings.  There are several
offerings of some classes and so the names of those classes show up
more than once in the name column.  I am trying to count the number of
unique names of classes.  So I need a way to filter out the doubles.
    Assume that I have the following table.  How can I determine how
many unique names are listed here?

Table 1.

Names   Ages
---------------------
Joe         12
Sally       13
Jim         12
Joe         11
Bob         16
Alex         14
Andy        14
Jude         5
Alex         8

Thanks for the help.

Andrew