function imgNumb() {
	imgNumb = document.getElementById('gal-wrapper').getElementsByTagName("div").length;
	maxImg = imgNumb - 3;
	minImg = 0;
	nowImg = 0;
	oldObj = 0;
}
function nextImg() {
  nowLeft = document.getElementById('gal-wrapper').style.left.replace('px', '');
  if (nowImg < maxImg) {
 	  document.getElementById('gal-wrapper').style.left = (nowLeft - 84) + 'px';
      nowImg++;
  }
}
function prevImg() {
  nowLeft = document.getElementById('gal-wrapper').style.left.replace('px', '');
  if (nowImg > minImg) {
 	  document.getElementById('gal-wrapper').style.left = (nowLeft*1 + 84) + 'px';
      nowImg--;
  }
}
function changeOpacity(numb, oldObj, i) {
   document.getElementById('mid-img').getElementsByTagName('a')[numb].style.opacity = i;
   document.getElementById('mid-img').getElementsByTagName('a')[oldObj].style.opacity = 1 - i;
}
function imgClick(numb) {
if (numb != oldObj) {
   document.getElementById('mid-img').getElementsByTagName('a')[numb].style.zIndex = 1;
   document.getElementById('mid-img').getElementsByTagName('a')[oldObj].style.zIndex = 0;
   for (i=0.1; i<=1; i=i+0.1) {
      changeOpacity(numb, oldObj, i);
   }
   oldObj = numb;
}
}