chrome.manifest no go here Rated 4 out of 5 stars

I followed the instructions given by nachdenki, however I am getting an "install scrip not found" error when I attempt to install the extension in FF.

Are the six lines of text all that is to be in the "chrome.manifest" file? Or are those lines to be added to the example shown at ?

Further, is "install.js" to be left in the .xpi, or is the "chrome.manifest" file to replace it?