Passing options to configure / compiler

[Vittorio]

I couldn't find in the docs how to pass options to the configure script.

For instance, I'm compiling postgresql under FreeBSD 5.3 stable.
After 'cd /usr/ports/databases/postgresql7' and ' make' a list of 
configure options is shown; among them I'm interested in "WITH_TESTS"" 
but I do not know how  to pass this option to the compiler (or to 
configure????).

Could you please help me?

Vittorio