var show;

function swapLayer( whichLayer )
{
  if( show != null && show != whichLayer ) {
    Effect.toggle(show,'appear', {duration:0.2});
    show = whichLayer; }
  else if( show == null )
	show = whichLayer;
  else
    show = null;

  Effect.toggle(whichLayer,'appear', {duration:0.2});
}

function showLayer( whichLayer )
{
  Effect.Appear(whichLayer);
}

// TODO: Browsercheck
function toggleLayer( whichLayer )
{
  var elem, vis;
  if( document.getElementById ) // this is the way the standards work
    elem = document.getElementById( whichLayer );
  else if( document.all ) // this is the way old msie versions work
      elem = document.all[whichLayer];
  else if( document.layers ) // this is the way nn4 works
    elem = document.layers[whichLayer];
  vis = elem.style;
  // if the style.display value is blank we try to figure it out here
  if(vis.display==''&&elem.offsetWidth!=undefined&&elem.offsetHeight!=undefined)
    vis.display = (elem.offsetWidth!=0&&elem.offsetHeight!=0)?'block':'none';
  vis.display = (vis.display==''||vis.display=='block')?'none':'block';
}

var submenu;

function showSubMenu( whichLayer )
{
  if( submenu != null && submenu != whichLayer ) {
    document.getElementById(submenu).style.display = 'none';
    submenu = whichLayer; }
  else if( submenu == null )
	submenu = whichLayer;
  else
    submenu = null;

  document.getElementById(whichLayer).style.display = 'block';
}