var ExpandIcon = "plus.gif";
var CollapseIcon = "minus.gif";

function toggle(node, aClose) 
{
  // expand, collapse
  var nextDIV = node.nextSibling;
  while (nextDIV.nodeName.toLowerCase() != "div") nextDIV = nextDIV.nextSibling;
  if (nextDIV.style.display == 'none') 
  {
    if (aClose){
      if (node.childNodes.length > 0) {
        if ((node.childNodes.item(0).nodeName.toLowerCase() == "img")&&(node.childNodes.item(0).className != "tvi-cat-img")) {
          node.childNodes.item(0).src = getImgDirectory(node.childNodes.item(0).src) + CollapseIcon;
          nextDIV.style.display = 'block';
        }
      }
    }else{
      if (node.previousSibling.childNodes.length > 0) {
        if ((node.previousSibling.childNodes.item(0).nodeName.toLowerCase() == "img")&&(node.previousSibling.childNodes.item(0).className != "tvi-cat-img")) {
          node.previousSibling.childNodes.item(0).src = getImgDirectory(node.previousSibling.childNodes.item(0).src) + CollapseIcon;
          nextDIV.style.display = 'block';
        }
      }
    }
  }
  else
  {
    if (node.childNodes.length > 0 && aClose == 1) {
      if ((node.childNodes.item(0).nodeName.toLowerCase() == "img")&&(node.childNodes.item(0).className != "tvi-cat-img")) {
        node.childNodes.item(0).src = getImgDirectory(node.childNodes.item(0).src) + ExpandIcon;
        nextDIV.style.display = 'none';
      }
    }
  }	
}

function getImgDirectory(source) {
  return source.substring(0, source.lastIndexOf('/') + 1);
}