var ver4 = (navigator.appVersion.charAt(0) >= "4");
var NN4  = ver4 && (navigator.appName == "Netscape");
var IE4 = ver4 && (navigator.appName.charAt(0) == "M");
var NN3 = ((navigator.appVersion.charAt(0) == "3") && (navigator.appName == "Netscape"));

if(NN3 || NN4 || IE4){
var imgB = new Array();
imgB[0] = new Image();  imgB[0].src = "img/topimg.jpg";
imgB[1] = new Image();  imgB[1].src = "img/topimg-1.jpg";
imgB[2] = new Image();  imgB[2].src = "img/topimg-2.jpg";
imgB[3] = new Image();  imgB[3].src = "img/topimg-3.jpg";
imgB[4] = new Image();  imgB[4].src = "img/topimg-4.jpg";
imgB[5] = new Image();  imgB[5].src = "img/topimg-5.jpg";
}

function Bin(nam,num) {
if(NN3 || NN4 || IE4) document.images[nam].src = imgB[num].src;
}

function Bout(nam,num) {
if(NN3 || NN4 || IE4) document.images[nam].src = imgB[num].src;
}