urgent help needed please help me out

i m trying to make a jar file for my package named as mainPanel

but when i run the gcs.jar file it gives following error" failed to load mainclass menifest attribute from e:/gcs/mainPanel/gcs.jar"

could you please explain me the procedure through an example for making a jar file for a package containing many subfolder.

[347 byte] By [deepakchaudhary24a] at [2007-11-26 17:01:03]