Javascript get the local file path in Mozilla

This function gives you the local file path of the file (nsIFile).

function getLocalFilePath(file) {
 // file is nsIFile
 var ios = Components.classes["@mozilla.org/network/io-service;1"]
                     .getService(Components.interfaces.nsIIOService);
 var fileHandler = ios.getProtocolHandler("file")
                     .QueryInterface(Components.interfaces.nsIFileProtocolHandler);
 var URL = fileHandler.getURLSpecFromFile(file);
 return URL;
}