pref("xpinstall.dialog.confirm", "chrome://mozapps/content/xpinstall/xpinstallConfirm.xul");
pref("xpinstall.dialog.progress.skin", "chrome://mozapps/content/extensions/extensions.xul?type=themes");
pref("xpinstall.dialog.progress.chrome", "chrome://mozapps/content/extensions/extensions.xul?type=extensions");
pref("xpinstall.dialog.progress.type.skin", "Extension:Manager-themes");
pref("xpinstall.dialog.progress.type.chrome", "Extension:Manager-extensions");
pref("extensions.update.enabled", true);
pref("extensions.update.interval", 86400);
pref("extensions.dss.enabled", false);
pref("extensions.dss.switchPending", false);
pref("extensions.ignoreMTimeChanges", false);
pref("extensions.logging.enabled", false);
pref("general.skins.selectedSkin", "classic/1.0");
// NB these point at AMO
pref("extensions.update.url", "chrome://mozapps/locale/extensions/extensions.properties");
pref("extensions.getMoreExtensionsURL", "chrome://mozapps/locale/extensions/extensions.properties");
pref("extensions.getMoreThemesURL", "chrome://mozapps/locale/extensions/extensions.properties");

const EMTYPE = "Extension:Manager";
  var wm = Components.classes["@mozilla.org/appshell/window-mediator;1"]
                     .getService(Components.interfaces.nsIWindowMediator);
  var theEM = wm.getMostRecentWindow(EMTYPE);
  if (theEM) {
    theEM.focus();
    return;
  }

  const EMURL = "chrome://mozapps/content/extensions/extensions.xul";
  const EMFEATURES = "chrome,menubar,extra-chrome,toolbar,dialog=no,resizable";
  window.openDialog(EMURL, "", EMFEATURES);