var NN3 = false;
t1= new Image();	t1.src = "images/none.gif";
t1on = new Image();	t1on.src = "images/t1.gif";
t2= new Image();	t2.src = "images/none.gif";
t2on = new Image();	t2on.src = "images/t2.gif";
t3= new Image();	t3.src = "images/none.gif";
t3on = new Image();	t3on.src = "images/t3.gif";
t4= new Image();	t4.src = "images/none.gif";
t4on = new Image();	t4on.src = "images/t4.gif";

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

function on(name)  {
        if (NN3) on3(name);
}
function off(name)  {
        if (NN3) off3(name);
}