var bannerArray = new Array();
var index=-2;

bannerArray[0] = "<img src='http://www.azulwasi.org/images/headers/header1.jpg'/>";
bannerArray[1] = "<img src='http://www.azulwasi.org/images/headers/header2.jpg'/>";
bannerArray[2] = "<img src='http://www.azulwasi.org/images/headers/header3.jpg'/>";

function imageRotate()
{
if(index<-1)index=Math.ceil(bannerArray.length*Math.random())-1;
if(index<0)index=bannerArray.length-1;
document.getElementById('masthead').innerHTML=bannerArray[index];
index=index-1;
setTimeout('imageRotate()',6000);
}