Java Applet Code Signing

step 1. Creat the keystore. (here my keystore name is mystore)
cmd>keytool -genkey -alias signFiles -keystore mystore -keypass password1 -dname "cn=emagination" -storepass password2

step 1.5. Preparing the jar files and crap..! ezz do it.

step 2. Sign ur applet. (here I am signing a UI.jar as SignedUI.jar)
jarsigner -keystore mystore -storepass password2 -keypass password1 -signedjar SignedUI.jar UI.jar signFiles

For real sign applet for production release:
Read this PDF provided by Verisign. Its pretty clear with steps.