window.addEventListener ? window.addEventListener("load",loadRandomBanner,false) : window.attachEvent("onload",loadRandomBanner);


function loadRandomBanner () {
	for(i=1;i<=;i++) {
		document.getElementById("bg_"+i).style.display = "none";
	}
	var a = Math.floor(Math.random() * ( - 1 + 1)) + 1;
	document.getElementById("bg_"+a).style.display = "block";
	setTimeout(loadRandomBanner,3000);
}