JDK 1.4 with JUnit

Hello Experts..

I am trying to run JUnit 3.8.1 with JDK 1.4 but I am getting the following exception:

java.lang.UnsupportedClassVersionError: com/ibm/testdatagenerator/AllTests (Unsupported major.minor version 50.0)
      at java.lang.ClassLoader.defineClass0(Native Method)
      at java.lang.ClassLoader.defineClass(ClassLoader.java:539)
      at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:123)
      at java.net.URLClassLoader.defineClass(URLClassLoader.java:251)
      at java.net.URLClassLoader.access$100(URLClassLoader.java:55)
      at java.net.URLClassLoader$1.run(URLClassLoader.java:194)
      at java.security.AccessController.doPrivileged(Native Method)
      at java.net.URLClassLoader.findClass(URLClassLoader.java:187)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:289)
      at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:274)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:235)
      at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.loadClass(RemoteTestRunner.java:683)
      at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.loadClasses(RemoteTestRunner.java:425)
      at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:445)
      at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673)
      at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386)
      at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)


any idea how to fix this? or what version of JUnit can run with JDK 1.4?