var num=0;

imgArray = [
  ['images/Investigations/Invest20080816_01.JPG','Group Photograph','1/8 - Group Photograph'],
  ['images/Investigations/Invest20080816_02.JPG','Small Light Anomaly','2/8 - Small Light Anomaly'],
  ['images/Investigations/Invest20080816_03.JPG','Small Light Anomaly','3/8 - Small Light Anomaly'],
  ['images/Investigations/Invest20080816_04.JPG','Small Light Anomaly','4/8 - Small Light Anomaly'],
  ['images/Investigations/Invest20080816_05.JPG','Small Light Anomaly Above TV','5/8 - Small Light Anomaly Above TV'],
  ['images/Investigations/Invest20080816_06.JPG','Is There A Figure In The Doorway','6/8 - Is There A Figure In The Doorway'],
  ['images/Investigations/Invest20080816_07.JPG','Enlarged Figure In The Doorway','7/8 - Enlarged Figure In The Doorway'],
  ['images/Investigations/Invest20080816_08.JPG','Small Light Anomaly','8/8 - Small Light Anomaly'],
]

function slideshow(slide_num) {
  document.getElementById('mypic').src=imgArray[slide_num][0];
  document.getElementById('mypic').alt=imgArray[slide_num][1];
  document.getElementById('burns').innerHTML=imgArray[slide_num][2];
}

function slideshowUp() {
  num++;
  num = num % imgArray.length;
  slideshow(num);
}

function slideshowBack() {
  num--;
  if (num < 0) {num=imgArray.length-1;}
  num = num % imgArray.length;
  slideshow(num);
}