Partial builds .....?

[Hari Ramasubbu]

My product has client and server binaries to be
built,How do i build just the client or server
provided i have only one build.xml file.

Can this be acheived by passing some variables as
properties in the build command line -D option and
processing those properties for building specing set
of targets.

essentially this is what i'm looking for

if client build     build set of client tasks
else                build set of server tasks

thanks
hari