var photo = new Array()
var photoNum = 0

photo[0] ="images/williams/1.jpg"
photo[1] ="images/williams/2.jpg"
photo[2] ="images/williams/3.jpg"
photo[3] ="images/williams/4.jpg"
photo[4] ="images/williams/5.jpg"
photo[5] ="images/williams/6.jpg"
photo[6] ="images/williams/7.jpg"
photo[7] ="images/williams/8.jpg"
photo[8] ="images/williams/9.jpg"
photo[9] ="images/williams/10.jpg"
photo[10] ="images/williams/11.jpg"
photo[11] ="images/williams/12.jpg"
photo[12] ="images/williams/13.jpg"
photo[13] ="images/williams/14.jpg"
photo[14] ="images/williams/15.jpg"
photo[15] ="images/williams/16.jpg"
photo[16] ="images/williams/17.jpg"
photo[17] ="images/williams/18.jpg"
photo[18] ="images/williams/19.jpg"
photo[19] ="images/williams/20.jpg"
photo[20] ="images/williams/21.jpg"
photo[21] ="images/williams/22.jpg"
photo[22] ="images/williams/23.jpg"
photo[23] ="images/williams/24.jpg"
photo[24] ="images/williams/25.jpg"
photo[25] ="images/williams/26.jpg"
photo[26] ="images/williams/27.jpg"
photo[27] ="images/williams/28.jpg"
photo[28] ="images/williams/29.jpg"
photo[29] ="images/williams/30.jpg"
photo[30] ="images/williams/31.jpg"
photo[31] ="images/williams/32.jpg"
photo[32] ="images/williams/33.jpg"
photo[33] ="images/williams/34.jpg"

function forward() {
  if (photoNum < photo.length - 1) {
    photoNum = photoNum + 1;
    document.images.gallery.src=photo[photoNum];
  }
  else {
    photoNum = 0;
    document.images.gallery.src=photo[photoNum];
  }
  imageNum();
}

function backward() {
  if (photoNum > 0) {
    photoNum = photoNum - 1;
    document.images.gallery.src=photo[photoNum];
  }
  else {
    photoNum = photo.length - 1;
    document.images.gallery.src=photo[photoNum];
  }
  imageNum();
}

function imageNum() {
  var imagediv = document.getElementById("position-string");
  imagediv.innerHTML = (photoNum + 1) + " of " + photo.length;
}