var num=0;

imgArray = [
  ['./images/doorreplace/image019.jpg','','2 Panel - Smooth'],
  ['./images/doorreplace/image021.jpg','','Pantry Door - Smooth'],
  ['./images/doorreplace/image023.jpg','','French Door - Smooth'],
  ['./images/doorreplace/image025.jpg','','4 Panel Arched Top - Textured'],
  ['./images/doorreplace/image027.jpg','','4 Panel - Smooth/Textured'],
  ['./images/doorreplace/image029.jpg','','6 Panel - Smooth/Textured'],
  ['./images/doorreplace/image031.jpg','','2 Panel Arched Top - Smooth/Textured'],
  ['./images/doorreplace/image033.jpg','','2 Panel Roman - Smooth'],
  ['./images/doorreplace/image035.jpg','','3 Panel - Textured'],
  ['./images/doorreplace/image037.jpg','','Beaded Arch Top - Smooth']
]

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);
}