FreeBSD Port Question

[VeeJay]

Hi guys

How can one find the location of the URL/FTP site where FreeBSD 6.1 fetches
the Source of a Distribution for example, mysql50???

I am trying to compile and install mysql50 at my freebsd61 web server from
source. I can install it from the ports easily and have done twice.
(location: /usr/ports/databases/mysql50-server/)

But I want to change the location of installation for "chroot" reason and
wanna configure with some paraments before compilation too. So, I have tried
A LOT to find the source distribution of mysql-50 for freebsd6x from
dev.mysql.com website or other mirros but with NO luck.
They only have the binary distribution of mysql50 for FreeBSD 6x.

My question is that how can I find the location of the site/ftp where from
FreeBSD61 fetches? I have tried to go through the "Makefile". But since I am
a novice, I cannot understand a bit what it says?

a snipt from Makefile:

PORTNAME?=      mysql
PORTVERSION=    5.0.2
PORTREVISION?=  0
CATEGORIES=     databases
MASTER_SITES=   ${MASTER_SITE_MYSQL}
MASTER_SITE_SUBDIR=     MySQL-5.0
PKGNAMESUFFIX?= -server
DISTNAME=       ${PORTNAME}-${PORTVERSION}-alpha

MAINTAINER=     ale at FreeBSD.org
COMMENT?=       Multithreaded SQL database (server)

WRKSRC=         ${WRKDIR}/${PORTNAME}-${PORTVERSION}-alpha
SLAVEDIRS=      databases/mysql50-client
PKGINSTALL?=    ${WRKDIR}/pkg-install
DB_DIR?=        /var/db/mysql
USE_LIBTOOL_VER=15
USE_REINPLACE=  yes
USE_RC_SUBR=    yes

-- 
Thanks!

BR / vj