delete column - Mailing list pgsql-general

I know this is an easy question, but I can't find any info on how do
this in the PostgreSQL book.  How do you delete a column?  I've been
able to delete tables, db's, rows, etc.  But can't figure out how to
just delete a column.  I'm running RedHat 7.2 and PostgreSQL 7.1

Thanks for any help.