var phototimeout_delay = 3000; // milliseconds
currentphoto = 0;
var photos = new Array(18);
photos[0] = "images/p10.jpg";
photos[1] = "images/p11.jpg";
photos[2] = "images/p18.jpg";
photos[3] = "images/p19.jpg";
photos[4] = "images/p20.jpg";
photos[5] = "images/p31.jpg";
photos[6] = "images/p32.jpg";
photos[7] = "images/p41.jpg";
photos[8] = "images/p42.jpg";
photos[9] = "images/p43.jpg";
photos[10] = "images/p44.jpg";
photos[11] = "images/p50.jpg";
photos[12] = "images/p51.jpg";
photos[13] = "images/p111.jpg";
photos[14] = "images/p112.jpg";
photos[15] = "images/p120.jpg";
photos[16] = "images/p200.jpg";
photos[17] = "images/p210.jpg";


function nextphoto() {
if (++currentphoto > photos.length-1) {
  currentphoto = 0;
}
  document.images.photoshow.src = photos[currentphoto];
}

function previousphoto() {

currentphoto = currentphoto -1;

if (currentphoto < 0) {
  currentphoto = photos.length-1
}
  document.images.photoshow.src = photos[currentphoto];
}

function startstopphoto() {
var text=document.getElementById('photosbutton').innerHTML
document.getElementById('photosbutton').innerHTML = (text == "Stop") ? "Start" : "Stop";
phototimeout();
}


function phototimeout() {
if (document.getElementById('photosbutton').innerHTML == "Stop") {
  nextphoto();
  window.setTimeout("phototimeout()", phototimeout_delay);
}
}