Retrieve columntypes and checks?

Trying to convert an application from MySQL to PostgreSQL I ran into
some troubles..

In MySQL is it quite easy to find out which type a column is.. in
particular if a column is an "enum" so the webapplication can do
appropiate checks in javascript in advance for an insert.

In PostgreSQL the enum's are converted to varchar with checks, so I need
to get a hold on the column-type and if it's a varchar parse the check
string for values..

How do I do that?

Any better suggestions?

Thanks.

--
./Jesper Krogh, jesper@krogh.cc