select statement for intersecting fields

[wxdqz]

What select statement should I use for the following if I were to get only the person who is both a "Clerk" and a "Salesman"?

sample table
-----------------------
employee
-----------------------
name job
----- -----
Mike Clerk
John Salesman
Bob Clerk
John Clerk
Biff Salesman
-----------------------

if I use "select * from employee where job = 'Clerk' and job = 'Salesman'", i get an empty field. any ideas? thanks.