function getLayerRef (id, document) {
	if (!document){
		document = window.document;}
		
		if (document.layers){
			for (var l = 0; l < document.layers.length; l++)
				if (document.layers[l].id==id)
					return document.layers[l];
			for (var l = 0; l < document.layers.length; l++){
				var result = getLayerRef(id.document.layers[l].document);
				if (result)
					return result;
			}
			return null;
		}else if (document.all){
			return document.all[id];
		}else if (document.getElementById){
			return document.getElementById(id);
			}
}

function setVisibility(objLayer, visible) {

  if(document.layers){
    objLayer.visibility  = 
        (visible == true) ? 'show' : 'hide';
  } else {
    objLayer.style.visibility = 
        (visible == true) ? 'visible' : 'hidden';
  }

}

function setVisibility4Layer(visible, d){
  if (!d)
    d = window.document;

  if(document.layers){
    for(var i=0; i < d.layers.length; i++) {
      setVisibility(d.layers[i], visible);
      setVisibility4Layer(visible, d.layers[i].document);
    }
  } else if(document.all) {
   
    for(i=0;i<document.all.tags("div").length;i++) 
      setVisibility(document.all.tags("div")[i], visible);
  } else if(document.getElementsByTagName) {
    var layers = document.getElementsByTagName("div");
    for(i=0; i < layers.length; i++)
      setVisibility(layers[i], visible);
  }
}