openMenu=false;
   
   var menu= new Array(3)
	 menu[0]="archivesMenu";
	 menu[1]="categoriesMenu"; 
	 menu[2]="authorsMenu"; 
	 menu[3]="linksMenu"; 

document.onclick = destroyLayers;

function destroyLayers(e) {
	
	if (!e) e = window.event;
  var el = e.target || e.srcElement;
	while (el.id != "topbarmenu" && el.id != "submenus" && (el = el.parentNode));
	if (!el && openMenu == true) {
			hideLayers();
			openMenu = false;
			
	}
}

function hideLayers() {
      for(i=0;i<menu.length;i++) hideLayer(menu[i]);
  }

function LayerSwitch(layerName)
  {
    if (openMenu == true) {
      hideLayers();
      showLayer(layerName);
  	}
  }

  function ToggleLayers(layerName)
  {
   	if (openMenu == false) {
    	openMenu=true;
      showLayer(layerName);
  	}
  	else {
  		hideLayers();
  		openMenu = false;
  	}
  }

  function showLayer(layerName)
  {
  	theLayer = document.getElementById(layerName);
    theLayer.style.visibility='visible';
  }
  function hideLayer(layerName)
  {
    theLayer = document.getElementById(layerName);
    theLayer.style.visibility='hidden';
  }