How to set individual package options?

["Thomas Mueller" <mueller6724%bellsouth.net@localhost>]

I've been reading through the pkgsrc guide but couldn't find how to set build 
options for the various packages.

FreeBSD ports collection shows a color text dialog box for each port to be 
built that has options.  User navigates with up- and down-arrows, Space, Tab 
and Enter.  One downside is not always knowing which key to press between 
Space, Tab and Enter and then not getting the desired options before the port 
starts to build.  Another downside is when a port has dependencies with 
options, then the build is interrupted for dialog-box input, for possibly hours 
at a time if the user is not watching continuously.  Question is how pkgsrc 
handles that, like for instance if I want to build editors/abiword or 
math/gnumeric.  I know both of these packages have dependencies, some may have 
user-configurable options.

I downloaded pkgsrc in NetBSD 5.1_RC4 and unpacked, haven't got to use yet, 
have been looking through and ran "make show-options".

Tom