var myPhotoGall = "";

for(var n = 1; n <= numPhotos; n++){
	myPhotoGall += "photo_" + n;
	if(n != numPhotos){
		myPhotoGall += ",";
	}
}

var photos = myPhotoGall.split(',');
var n = 0;

function moveSlides(way){
	document.getElementById(photos[n]).style.display = "none";
	if(way == 1){
		n--;
	} else {
		n++;
	}
	if (n < 0) {
			n = (numPhotos-1);
	}
	if (n > (numPhotos -1)) {
			n = 0;
	}
	document.getElementById(photos[n]).style.display = "block";
}