NWDI Build in Errors

hi,

i am getting following error while trying to activate the activities in NWDI:

Ant runtime 12.375 seconds

Ant build finished with ERRORS

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

Error: Build stopped due to an error: 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

Build plugin finished at 2009-12-02 10:19:58 GMT+05:30 (IST)

Total build plugin runtime: 13.609 seconds

Build finished with ERROR

pls guide me to resolve trhe issue.

Regards,

Pavani