logic/db question

hi...

i have a tbl
 fooTBL
   name
   parentID
   ID

so a name can have might have a parentID, as well as an ID. 'name's are
associated with other 'name's via the parentID. in other words, if a name's
parentID == a name's ID, name1 is the parent of name2.

  name    parentID     ID
  foo         -        1
  cat        1        2
  dog      2        3

my question, how can i come up with a sql query that will list all the
children (and children's children...) of a top level item?

i had done this awhile ago.. but can't recall how i did it..

thanks