Installation of JDK 1.2.1 for Windows ME

hi all,JDK version 1.2.1installation done !path set !can compile !But cannot runerror message="exception in thread "main" java.lang.noclassDeffound"Pls help !Thank !
[249 byte] By [calvin_1982] at [2007-9-26 2:59:03]
# 1
1) if you have set the classpath, unset it. (with "set classpath="). If you have a package declaration in the source, remove it and recompile.2) run with java ClassName, that is, without the .class-extension from the directory where the class file is.
jsalonen at 2007-6-29 10:54:41 > top of Java-index,Desktop,Deploying...