var delay = 7000; // time delay between rotates, 1000 = 1 second


// Use same path here as above
var imgArray = new Array()
   imgArray[0] = "images/banner1.jpg";
   imgArray[1] = "images/banner2.jpg";
   imgArray[2] = "images/banner3.jpg";
   imgArray[3] = "images/banner4.jpg";

function rotateImage(imgNo)
{
   clearTimeout(timerId);
   var index = imgNo++ % imgArray.length; 
   document.getElementById('image_swap').src = imgArray[index];
   timerId = setTimeout("rotateImage(" + imgNo + ")", delay);
}

// Wait a bit before starting the rotation
var timerId = setTimeout('rotateImage(0)', 0);