Calling Java applets methods using DOM and JavaScriptTag(s): Javascript interaction
[IE4 or better] <OBJECT ID="myApplet" ...> ... <PARAM NAME="scriptable" value="true"> <PARAM NAME="mayscript" value="true"> ... </OBJECT> [in your script] document.all.myApplet.myMethod()
You use the mayscript parameter if you call Javascript function from Java.
This Sun's document describes how Java to Javascript communication works when using the Java Plug-in.