[dmitri22]

Рабочий код.

function changeProxy (currentIP, currentPort) { // Добавляет прокси в настройках Firefox

	var iphttp=   currentIP;
	var ipssl=    currentIP;
	var ipftp=    '';
	var ipsocks=  '';
	var socksver= '5';
	var portall=  currentPort;
	var logAndPassProxy = '';

	var prefs = Components.classes["@mozilla.org/preferences-service;1"].getService(Components.interfaces.nsIPrefBranch);

	// manual proxy configuration
	prefs.setIntPref("network.proxy.type", 1);

	// use the proxy server for all protocols
	 prefs.setBoolPref("network.proxy.share_proxy_settings", true);
	// each proxy independent
	prefs.setBoolPref("network.proxy.share_proxy_settings", false);

	// HTTP Proxy
	prefs.setCharPref("network.proxy.http", iphttp);
	prefs.setIntPref("network.proxy.http_port", portall);

	// SSL Proxy
	prefs.setCharPref("network.proxy.ssl", ipssl);
	prefs.setIntPref("network.proxy.ssl_port", portall);

	// FTP Proxy
	prefs.setCharPref("network.proxy.ftp",ipftp);
	prefs.setIntPref("network.proxy.ftp_port",portall);

	// SOCKS Host
	prefs.setCharPref("network.proxy.socks", ipsocks);
	prefs.setIntPref("network.proxy.socks_port", portall);
	prefs.setIntPref("network.proxy.socks_version", socksver);

	// login & password proxy
	//prefs.setCharPref("extensions.proxyauth.authtoken",logAndPassProxy);

}

ip = "192.168.1.1";
port = "1234";

changeProxy (ip, port);