var layerBgDivOrgPos = 0;
var layerDivOrgPos = 0;

var layerVisible = 0;

function showLayer(imgSrcStr)
{
  var layerBgDiv = document.getElementById('layerBgDiv');
  var layerDiv = document.getElementById('layerDiv');

  layerBgDivOrgPos = layerBgDiv.style.top;
  layerDivOrgPos = layerDiv.style.top;

  var scrollTop = document.body.scrollTop;

  layerBgDiv.style.top = layerBgDivOrgPos + scrollTop;
  layerDiv.style.top = layerDivOrgPos + scrollTop;

  layerBgDiv.style.visibility = 'visible';
  layerDiv.style.visibility = 'visible';

  document.popupImg.src = imgSrcStr;

  layerVisible = 1;
}

function hideLayer()
{
  var layerBgDiv = document.getElementById('layerBgDiv');
  var layerDiv = document.getElementById('layerDiv');

  layerBgDiv.style.visibility = 'hidden';
  layerDiv.style.visibility = 'hidden';

  layerBgDiv.style.top = layerBgDivOrgPos;
  layerDiv.style.top = layerDivOrgPos;

  document.popupImg.src = '/images/beeldmerk.jpg';

  layerVisible = 0;
}