Erro ao copilar

[sheah]

Buildfile: C:\Documents and Settings\GiovanniM3\workspace\*********_CORE\build .xml
clean:
[delete] Deleting directory C:\Documents and Settings\GiovanniM3\workspace\*********_CORE\build
init:
[mkdir] Created dir: C:\Documents and Settings\GiovanniM3\workspace\*********_CORE\build
[mkdir] Created dir: C:\Documents and Settings\GiovanniM3\workspace\*********_CORE\build \classes
[mkdir] Created dir: C:\Documents and Settings\GiovanniM3\workspace\*********_CORE\build \dist
[mkdir] Created dir: C:\Documents and Settings\GiovanniM3\workspace\*********_CORE\build \dist\doc
[mkdir] Created dir: C:\Documents and Settings\GiovanniM3\workspace\*********_CORE\build \dist\*********_LoginServer
[mkdir] Created dir: C:\Documents and Settings\GiovanniM3\workspace\*********_CORE\build \dist\*********_GameServer
version:
[exec] Result: 1
[echo] Revision: svn: E155036: Working copy 'C:\Documents and Settings\GiovanniM3\workspace\*********_CORE' is too old (format 10, created by Subversion 1.6)
compile:
[javac] Compiling 1384 source files to C:\Documents and Settings\GiovanniM3\workspace\*********_CORE\build \classes

BUILD FAILED
C:\Documents and Settings\GiovanniM3\workspace\*********_CORE\build .xml:61: Unable to find a javac compiler;
com.sun.tools.javac.Main is not on the classpath.
Perhaps JAVA_HOME does not point to the JDK.
It is currently set to "C:\Arquivos de programas\Java\jre7"Total time: 1 second

Oque é isso ? :(