Solution : projects\connectfour\build.xml:46: Unable to find a javac compiler; com.sun.tools.javac.Main is not on the classpath. Perhaps JAVA_HOME

make sure you are bale to execute the javac from command line.
[basically you need to have the "C:\Program Files\Java\jdk1.6.0_16\bin" included in you path]

or following user variable

JAVA_HOME = C:\Program Files\Java\jdk1.6.0_16

copy the tools.jar from C:\Program Files\Java\jdk1.6.0_16\lib folder to cruisecontrol\apache-ant-1.7.0\lib

This should do the Job

- Mihir Patel