function hideLayer(sel) {
  var eles = document.getElementsByTagName("div");
  var cont = document.getElementsByTagName("container");
  var header = document.getElementsByTagName("h2");
  var all = (sel) ? 0 : 1;
  if(all){
  		  for(i=0;i<eles.length;i++) {
		  document.getElementById(eles[i].id).style.visibility="hidden";
		  document.getElementById(eles[i].id).style.display="none";
		  }
  } else {
  		  for(i=0;i<eles.length;i++) {
		     if(eles[i].id==sel) {
		        document.getElementById(eles[i].id).style.visibility="hidden";
		        document.getElementById(eles[i].id).style.display="none";
		     }
		  }
  }
  }

  function showLayer(sel) {
  var eles = document.getElementsByTagName("div");
  for(i=0;i<eles.length;i++) {
  		if (eles[i].id==sel) {
			document.getElementById(sel).style.visibility="visible";
			document.getElementById(sel).style.display="block";
			}
  }
  }
function toggleLayer(sel) {
	var vis = document.getElementById(sel).style.display;
	if (vis == "block") { 
		document.getElementById(sel).style.display = "none";
	}
	else { document.getElementById(sel).style.display = "block"; }
}