var num=0;

imgArray = [
  ['images/Investigations/Invest20081031_01.JPG','Group Photograph','1/16 - Group Photograph'],
  ['images/Investigations/Invest20081031_02.JPG','Who Is Sitting In The Dress Circle?','2/16 - Who Is Sitting In The Dress Circle?'],
  ['images/Investigations/Invest20081031_03.JPG','Multiple Light Anomalies','3/16 - Multiple Light Anomalies'],
  ['images/Investigations/Invest20081031_04.JPG','Multiple Light Anomalies','4/16 - Multiple Light Anomalies'],
  ['images/Investigations/Invest20081031_05.JPG','Light Anomaly Moving Fast','5/16 - Light Anomaly Moving Fast'],
  ['images/Investigations/Invest20081031_06.JPG','Light Anomaly','6/16 - Light Anomaly'],
  ['images/Investigations/Invest20081031_07.JPG','Multiple Light Anomalies','7/16 - Multiple Light Anomalies'],
  ['images/Investigations/Invest20081031_08.JPG','Light Anomaly','8/16 - Light Anomaly'],
  ['images/Investigations/Invest20081031_09.JPG','Multiple Light Anomalies','9/16 - Multiple Light Anomalies'],
  ['images/Investigations/Invest20081031_10.JPG','Light Anomaly','10/16 - Light Anomaly'],
  ['images/Investigations/Invest20081031_11.JPG','Light Anomaly','11/16 - Light Anomaly'],
  ['images/Investigations/Invest20081031_12.JPG','Multiple Light Anomalies','12/16 - Multiple Light Anomalies'],
  ['images/Investigations/Invest20081031_13.JPG','Multiple Light Anomalies','13/16 - Multiple Light Anomalies'],
  ['images/Investigations/Invest20081031_14.JPG','Multiple Light Anomalies','14/16 - Multiple Light Anomalies'],
  ['images/Investigations/Invest20081031_15.JPG','Light Anomaly','15/16 - Light Anomaly'],
  ['images/Investigations/Invest20081031_16.JPG','Light Anomaly','16/16 - 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);
}