function openIMG(ID, poleIMG){
  div = document.getElementById('divIMG');
  div_img = document.getElementById('divIMGsrc');

  if(div) div.style.display = 'block';
  if(div_img) div_img.src = poleIMG[ID];
  pointerIMG = ID;
  return;

}
function closeIMG(){
  div = document.getElementById('divIMG');
  if(div) div.style.display = 'none';
  return;
}

function openNextIMG(pointerIMG, poleIMG){
  if((pointerIMG + 1) > (poleIMG.length - 1)) pointerIMG = 0;
    else pointerIMG += 1;
  openIMG(pointerIMG, poleIMG);
  return;
}

function openPrevIMG(pointerIMG, poleIMG){
  if((pointerIMG - 1) < 0) pointerIMG =  poleIMG.length - 1;
    else pointerIMG -= 1;
  openIMG(pointerIMG, poleIMG);
  return;
}