jdk1.3 compile problem

[asolomon15]

Hello everyone... I seem to have a problem when I try to build jdk13
port on freebsd5.1 release.  Here are the errors that I get

# Start of jdk build
i386 Build started:   1.3.1-p8-daddius-031105-21:52
ERROR: Your BOOTDIR environment variable does not point
       to a valid Java 2 SDK for bootstrapping this build.
       A Java 2 SDK 1.3.1 build must be bootstrapped against any
       1.3 build. Please update your ALT_BOOTDIR setting, or
       just unset it, and start your build again.
 
Exiting because of the above error(s).
gmake: *** [sanity] Error 1
*** Error code 2
 
Stop in /usr/ports/java/jdk13.