visit the following url in IE:

http://sqeweb/jsn/users/fred/deployment_ws/reappear/deployment_6_UR_int_ws/deployment/src/plugin/FunctionalTest/FunctionalTest/html/SetFrameApplet.html

an exception will be thrown:
sun.plugin.dom.exception.BrowserNotSupportedException: netscape.javascript.JSException: No such property "contentDocument" on JavaScript object

it can work under firefox3

the source code of applet is:
http://sqeweb/jsn/users/fred/deployment_ws/reappear/deployment_6_UR_int_ws/deployment/src/plugin/FunctionalTest/FunctionalTest/src/SetFrameApplet.java
The same function implemeted by javascript can be found on:

http://sqeweb/jsn/users/fred/deployment_ws/reappear/deployment_6_UR_int_ws/deployment/src/plugin/FunctionalTest/FunctionalTest/html/SetFrameScript.html

this can work on both IE and firefox