window.onload = changeImage;


var myPix = new Array ("imagesBB/img01.jpg","imagesBB/img02.jpg","imagesBB/img03.jpg");

function changeImage() {
	
	 setInterval("choosePic()", 4000);
	
	}

function choosePic() {
	randomNum = Math.floor((Math.random() * myPix.length));
	document.getElementById("imageTop").src = myPix[randomNum];
}