window.onload = rotate;

var adImages = new Array("images/ad_rotate_1.png","images/ad_rotate_2.png","images/ad_rotate_3.png","images/ad_rotate_4.png");
var thisAd = 2;

function rotate() {
	thisAd++;
	if (thisAd == adImages.length) {
		thisAd = 0;
	}
	
	document.getElementById("adBanner").src=adImages[thisAd];
	setTimeout("rotate()", 5*1000);
}