function ShowHideTree(upperNodeID, nodeNum)
{
var debug = document.getElementById('debug');
  var node = document.getElementById(upperNodeID + '_' + nodeNum);
  if (node)
  {
    if (node.style.display == 'none')
    {
      for (var index = 0; index < nodeNum; index++)
      {
        var otherNode = document.getElementById(upperNodeID + '_' + index);
        if (otherNode)
        {
          if (otherNode.style.display != 'none') otherNode.style.display = 'none';
        }
      }
      for (var index = nodeNum + 1; index < 100; index++)
      {
        var otherNode = document.getElementById(upperNodeID + '_' + index);
        if (otherNode)
        {
          if (otherNode.style.display != 'none') otherNode.style.display = 'none';
        }
        else break;
      }
      //sbalit podnody?
      node.style.display = 'block';
    }
    else
    {
      node.style.display = 'none';
    }
  }
}