[GENERAL] Another Regular Expression "Problem"

Hopefully I'm not being dense again ...

I've got a CGI frontend that I'd like to give users the ability to type
in regular expressions into forms and do queries based up this data.
During testing things work fine as long as I keep with simple
expressions like:

select "first", "last" from "employees" where "first" ~ '^Charles'

But if I do something like the following, I get nothing:

select "first", "last" from "employees" where "first" ~
'^(Charles)|(James)'

I looked down in src/backend/regex at re_format.7 and this is explained
in that document as "extended" RE's. I've tried this RE with egrep and
it matches lines like I want (pretty simple stuff here). What gives?
--
Charles Curley, Staff Engineer
Computer Integrated Manufacturing
Lockheed Martin Ocala Operations