Getting Javascript working with ANT

[Vo, David \(Mission Systems\)]

Hi
 
I am having trouble getting javascript working with ANT version 1.6.5. I have 
/usr/local/ant/lib in the path. I also downloaded bsf.jar and rhino.jar 
(renamed to js.jar) in the same folder. I keep getting the same error messages:
 
BUILD FAILED
file:/home/builds/build/si3-cc-build-nightly-notag.xml:74: Could not create 
task or type of type: script.
 
Ant could not find the task or a class this task relies upon.
 
This is common and has a number of causes; the usual
solutions are to read the manual pages then download and
install needed JAR files, or fix the build file:
 - You have misspelt 'script'.
   Fix: check your spelling.
 - The task needs an external JAR file to execute
   and this is not found at the right place in the classpath.
   Fix: check the documentation for dependencies.
   Fix: declare the task.
 - The task is an Ant optional task and optional.jar is absent
   Fix: look for optional.jar in ANT_HOME/lib, download if needed
 - The task was not built into optional.jar as dependent
   libraries were not found at build time.
   Fix: look in the JAR to verify, then rebuild with the needed
   libraries, or download a release version from apache.org
 - The build file was written for a later version of Ant
   Fix: upgrade to at least the latest release version of Ant
 - The task is not an Ant core or optional task
   and needs to be declared using <taskdef>.

This is my javascript (code not mine):
 
<target name="cc2cvstimestamps">
  <echo message="Converting Timestamps" />
               <script language="javascript">
          <![CDATA[     
          importClass(java.text.SimpleDateFormat);
          cc_formatter = new SimpleDateFormat("yyyyMMddHHmmss");
          cvs_formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
 
          date = cc_formatter.parse(project.getProperty("cctimestamp"));  
          project.setProperty("cvstimestamp", cvs_formatter.format(date));
          date = 
cc_formatter.parse(project.getProperty("cclastgoodbuildtimestamp"));  
          project.setProperty("cvslastgoodbuildtimestamp", 
cvs_formatter.format(date));
   ]]> 
        </script>
         </target>
 
I am using a pre-compiled version. I did not build Ant. Any help would be 
appreciated.
 
Thanks,
David