... does the overlay know where to overlay itself? The IDs of the overlay children and the original XUL are matched to find the target within the files, but the manifest that accompanies the overlay ... package, the "fly skin," and the existing component it interacts with, the communicator the default Mozilla browser (the syntax and structure is the same for all manifests, however). The ... make these additions to the installed-chrome.txt file and restart Mozilla, the chrome registry looks for manifests in the directories you specify and registers the packages described there. The...