Thank you all, for your contribution . But I cannot compile package name . E.g package world; public class HelloWorld{ public static void main(
String args ){ System.out.println("HelloWorld"); } } each time I compile package name like this it gives error:NoClassDefError wrong world/HelloWorld. But I created a folder on world in C: \ directory of my harddisk and configure the classpath like .;C: \ world in the environmental variable in Windows XP, and enter javac to compile it, it compile and enter
java to run it it gives error:NoClassDefFoundError wrong World. This is the problem I am facing right now, please help!