This page (http://java.sun.com/javase/6/docs/technotes/guides/jar/jarGuide.html) leads me to believe that I should have access to the public "helper" class methods as well. "Note that the familiar CODE=myApplet.class parameter must still be present. The CODE parameter, as always, identifies the name of the applet where execution begins. However, the class file for the applet and all of its helper classes are loaded from the JAR file. "
For starters, I'd use just the APPLET tag these days, not EMBED or OBJECT. That has no bearing on the problem at hand, though.
The fact that the applet is delivered as a jar file also has no bearing on this.
The thing is, document.uploadAppletFF is a reference to the class that extends (J)Applet, and that's all you get. If you want to call methods in other classes, then you need to channel the call through a method the Applet subclass - you can't call other classes directly, since you don't have a reference to them.
Ah, I see. I didn't realize you only got a reference to the class that extended Applet; thought the jar changed that.