HWI not working - HTTP ERROR 500

I tried to use hive HWI to write hive queries on a UI.
As p[er the steps mentioned here https://cwiki.apache.org/confluence/display/Hive/HiveWebInterface
I set Ant and ran the hive hwi service.

but In browser when i hit http://localhost:9999/hwi i got the below error
HTTP ERROR 500

Problem accessing /hwi/. Reason:

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 "/usr/java/jdk1.6.0_32/jre"
Caused by:

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 "/usr/java/jdk1.6.0_32/jre"
at org.apache.tools.ant.taskdefs.compilers.CompilerAdapterFactory.getCompiler(CompilerAdapterFactory.java:129)

I have checked and changed JAVA_HOME. But its still the same