Java Applet Sign

Question

I have written an applet with Netbeans. When I click on Clean and Build then Netbean create a jar file "Test.jar" and also another folder called lib in the same directory. I've signed the Test.jar. Basically this applet upload files to server with FTP. So when Applet loads into browser then I am able to select files but when I click on upload then it stops. So my question is:

1. Have I also need to sign all dependent jar files?
2. My directory structure is as follow:

C:\AppletPage.html C:\Test.jar C:\lib

and code in html file is as follow

<applet code="UploadGUI.class"
archive="test.jar"
width=400 height=400>

Please advice me where am I wrong?

Thanks in Advance