ok = (((navigator.appName == "Netscape") && (parseInt(navigator.appVersion) >=3 )) ||
((navigator.appName == "Microsoft Internet Explorer") && (parseInt(navigator.appVersion)
>= 4 )))

if (ok)
{


bt1an = new Image();
bt1an.src = "img/bt1d.gif";
bt2an = new Image();
bt2an.src = "img/bt2d.gif";
bt3an = new Image();
bt3an.src = "img/bt3d.gif";
bt4an = new Image();
bt4an.src = "img/bt4d.gif";
bt5an = new Image();
bt5an.src = "img/bt5d.gif";

bt6an = new Image();
bt6an.src = "../img/bt1a.gif";
bt7an = new Image();
bt7an.src = "../img/bt2a.gif";
bt8an = new Image();
bt8an.src = "../img/bt3a.gif";
bt9an = new Image();
bt9an.src = "../img/bt4a.gif";
bt10an = new Image();
bt10an.src = "../img/bt5a.gif";
bt11an = new Image();
bt11an.src = "../img/bt6a.gif";
bt12an = new Image();
bt12an.src = "../img/bt7a.gif";


bt1aus = new Image();
bt1aus.src = "img/bt1c.gif";
bt2aus = new Image();
bt2aus.src = "img/bt2c.gif";
bt3aus = new Image();
bt3aus.src = "img/bt3c.gif";
bt4aus = new Image();
bt4aus.src = "img/bt4c.gif";
bt5aus = new Image();
bt5aus.src = "img/bt5c.gif";

bt6aus = new Image();
bt6aus.src = "../img/bt1.gif";
bt7aus = new Image();
bt7aus.src = "../img/bt2.gif";
bt8aus = new Image();
bt8aus.src = "../img/bt3.gif";
bt9aus = new Image();
bt9aus.src = "../img/bt4.gif";
bt10aus = new Image();
bt10aus.src = "../img/bt5.gif";
bt11aus = new Image();
bt11aus.src = "../img/bt6.gif";
bt12aus = new Image();
bt12aus.src = "../img/bt7.gif";

}
function img_act(imgName)
{
if (ok)
{
imgOn = eval(imgName + "an.src");
document [imgName].src = imgOn;
}
}
function img_inact(imgName)
{
if (ok)
{
imgOff = eval(imgName + "aus.src");
document [imgName].src = imgOff;
}
}