var imgs1 = new Array("images/siliconvalley.jpg","images/rocks.jpg","images/cloud.jpg","images/waterfall.jpg","images/stream.jpg","images/leaves.jpg","images/delta.jpg","images/bridgelight.jpg","images/flower.jpg","images/whiteflower.jpg","images/brickwall.jpg","images/river.jpg","images/peachflower.jpg","images/birds.jpg","images/waterplant.jpg","images/redhouse.jpg");
var alt1 = new Array();
var currentAd1 = 0;
var imgCt1 = imgs1.length;
function cycle1() {
  /*if (currentAd1 == imgCt1) {
    currentAd1 = 0;
  }
*/
	var l = imgs1.length;

	var rnd_no = Math.floor(l*Math.random());
	currentAd1 = rnd_no;

var banner1 = document.getElementById('adBanner1');
var link1 = document.getElementById('adLink1');
  banner1.src=imgs1[currentAd1]
  banner1.alt=alt1[currentAd1]
  /*currentAd1++;*/
}
  window.setInterval("cycle1()",10000);