importing applet in web page problem

this is the message I get when somebody opens the site and starts the applet, if I open the site on the servercomputer where all the files are I don't have this problem, it runs the applet as it has to be.

This is the message I get:

Error loading class:Demo4
java.lang.NoClassDefFoundError
java.lang.ClassNotFoundException:Demo4
at com/ms/vm/loader/URLClassLoader.loadClass
at com/ms/vm/loader/URLClassLoader.loadClass
at com/ms/applet/AppletPanel.securedClassLoad
at com/ms/applet/AppletPanel.processSentEvent
at com/ms/applet/AppletPanel.processSentEvent
at com/ms/applet/AppletPanel.run
at java/lang/Thread.run

I also want to say that I use java 1.4.0

Please help me with my problem

Thank you

Java applets on webpages need one or more .class and/or .jar files to work. Maybe your server only allows .html, .htm, .jpg, .gif, .txt to go out, but no .class and/or .jar files.