var squaresVisible = true;
var imgDivSquaresVisible = false;
var imgDivBoxesVisible   = true;

function showLargeSquaresImg(imgName, imgTitle)
{
  imgEl = document.getElementById('imgLarge');

  // hide squares title image if necessary
  imgInitialEl = document.getElementById('imgInitial');
  if (squaresVisible)
  {
    squaresVisible = false;
    imgInitialEl.style.visibility = 'hidden';
    imgInitialEl.style.display = 'none';
  }

  // show large image box if necessary
  imgDivEl = document.getElementById('imgLrg');
  if (!imgDivSquaresVisible)
  {
    imgDivSquaresVisible = true;;
    imgDivEl.style.visibility = 'visible';
    imgDivEl.style.display = 'block';
  }

  // set large image transparent
  var imgPath = '/img/imgDiv.gif';
  imgEl.src = imgPath;
  imgEl.alt = '';
  imgEl.title = '';

  // show new large image
  imgPath = '/img/quadrate/' + imgName + '_L.jpg';
  imgEl.src = imgPath;
  imgEl.alt = imgTitle;
  imgEl.title = imgTitle;
}


function showLargeBoxesImg(imgName, imgTitle)
{
  imgEl = document.getElementById('imgLarge');

  // show large image box if necessary
  imgDivEl = document.getElementById('imgLrg');
  if (!imgDivBoxesVisible)
  {
    imgDivBoxesVisible = true;;
    imgDivEl.style.visibility = 'visible';
    imgDivEl.style.display = 'block';
  }

  // set large image transparent
  var imgPath = '/img/imgDiv.gif';
  imgEl.src = imgPath;
  imgEl.alt = '';
  imgEl.title = '';

  // show new large image
  imgPath = '/img/kisten/' + imgName + '_L.jpg';
  imgEl.src = imgPath;
  imgEl.alt = imgTitle;
  imgEl.title = imgTitle;
}