Help - can't compile - Compiler class: 'com.sun.tools.javac.Main', not found

[Stefan]

I'm using Ant to compile a set of proprietary frameworks. I think I
have set up CLASSPATH etc correctly, but I keep getting the following
error when trying to build. Anyone have any ideas of what I should
try? Thanks!!

[ejbc] Compiler class: 'com.sun.tools.javac.Main', not found
[ejbc] java.lang.ClassNotFoundException: com.sun.tools.javac.Main
[ejbc] at java.net.URLClassLoader$1.run(URLClassLoader.java:199)
[ejbc] at java.security.AccessController.doPrivileged(Native
Method)
[ejbc] at java.net.URLClassLoader.findClass(URLClassLoader.java:187)
[ejbc] at java.lang.ClassLoader.loadClass(ClassLoader.java:289)
[ejbc] at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:274)
[ejbc] at java.lang.ClassLoader.loadClass(ClassLoader.java:235)
[ejbc] at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:302)
[ejbc] at java.lang.Class.forName0(Native Method)
[ejbc] at java.lang.Class.forName(Class.java:141)
[ejbc] at weblogic.utils.compiler.CompilerInvoker.compileMaybeExit(CompilerInvoker.java:407)
[ejbc] at weblogic.utils.compiler.CompilerInvoker.compile(CompilerInvoker.java:329)
[ejbc] at weblogic.utils.compiler.CompilerInvoker.compile(CompilerInvoker.java:337)
[ejbc] at weblogic.ejb20.ejbc.EJBCompiler.doCompile(EJBCompiler.java:270)
[ejbc] at weblogic.ejb20.ejbc.EJBCompiler.compileEJB(EJBCompiler.java:476)
[ejbc] at weblogic.ejb20.ejbc.EJBCompiler.compileEJB(EJBCompiler.java:397)
[ejbc] at weblogic.ejbc20.runBody(ejbc20.java:519)
[ejbc] at weblogic.utils.compiler.Tool.run(Tool.java:146)
[ejbc] at weblogic.utils.compiler.Tool.run(Tool.java:103)
[ejbc] at weblogic.ejbc.main(ejbc.java:29)