var NN3 = false;

eng= new Image(); eng.src = "img/eng.jpg"; engon = new Image(); engon.src = "img/eng1.jpg";
cz= new Image(); cz.src = "img/cz.jpg"; czon = new Image(); czon.src = "img/cz1.jpg";
ru= new Image(); ru.src = "img/ru.jpg"; ruon = new Image(); ruon.src = "img/ru1.jpg";

function on3(name)	{document[name].src = eval(name + "on.src");}
function off3(name)	{document[name].src = eval(name + ".src");}
NN3 = true;
function on(name)	{if (NN3) on3(name);}
function off(name)	{if (NN3) off3(name);}