var mainpage = false;

var compat = (document.images);

//preloading images
if (compat){
var left1 = new Image(23,23);
left1.src = "images/goleft1.gif";
var left2 = new Image(23,23);
left2.src = "images/goleft2.gif";
var right1 = new Image(23,23);
right1.src = "images/goright1.gif";
var right2 = new Image(23,23);
right2.src = "images/goright2.gif";
}

function flip(n,obj){
if (compat)
document.images[n].src = obj.src;
}