applet work well in appletviewer but do not work within browser

hi, i created an applet that works well in appletviewer,but it does not work within a firefox browser, it issue a message: java.security.AccessControlException: access denied (java.io.FilePermission imgDir/vsam.jpg read). What can i do to solve this issue please ?
[271 byte] By [edusora] at [2007-10-3 1:15:53]
# 1

sign the applet, use doprivileged and trust the applet when you open it.

Use htmlconverter in jdk/bin folder to convert you applet so it uses

object tag instead of applet so IE won't try to run it with msjvm.

Signing applets:

http://forum.java.sun.com/thread.jsp?forum=63&thread=524815

second post and reply 18 for the java class file using doprivileged

Still problems?

A Full trace might help us out:

http://forum.java.sun.com/thread.jspa?threadID=656028

harmmeijera at 2007-7-14 18:13:02 > top of Java-index,Security,Signed Applets...