Main-Class: YourClassThatContainsAMainMethodI'm about sure that other kind people will supply you with the links to
to it, AND add a newline at the end of the text-file. Then use the command
provided you have the Manifest.txt file in the current directory and the .class files in a subdirectory named yourpackage (i.e. your class belongs to a package named yourpackage).
jar cmf Manifest.txt JarName.jar yourpackage/*.class