var dimages=new Array();
var numImages=4;   //edit here for total number of images 

for (i=0; i<numImages; i++) {
	dimages[i]=new Image();
	dimages[i].src="media/photo"+(i+1)+".jpg";
}

var curImage=-1;


 
function swapPicture() {
	if (document.images) {
		var nextImage=curImage+1;

		if (nextImage>=numImages)   
			nextImage=0;          
		if (dimages[nextImage] && dimages[nextImage].complete) {
			var target=0;
			if (document.images.myImage)
				target=document.images.myImage;
			if (document.all && document.getElementById("myImage"))
				target=document.getElementById("myImage");
  
			// make sure target is valid.  It might not be valid if the page has not finished loading
			if (target) {
				target.src=dimages[nextImage].src;
				curImage=nextImage;
			}
 			setTimeout("swapPicture()", 2000);
		}
		else {
			setTimeout("swapPicture()", 500);
		}
		}
	}
 
setTimeout("swapPicture()", 2000);