var num=0;

imgArray = [
  ['../images/kids4kids/1.jpg','photo',''],
  ['../images/kids4kids/2.jpg','photo',''],
  ['../images/kids4kids/3.jpg','photo', '']
]

function slideshow(slide_num) {
  document.getElementById('mypic1').src=imgArray[slide_num][0];
  document.getElementById('mypic1').alt=imgArray[slide_num][1];
  document.getElementById('burns1').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);
}