function hideLayer(sel) {
  var eles = document.getElementsByTagName("div");
  var cont = document.getElementsByTagName("container");
  var header = document.getElementsByTagName("h3");
  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";
			}
  }
  }

/*back to top*/
function backToTop() {
 var x1 = x2 = x3 = 0;
 var y1 = y2 = y3 = 0;

 if (document.documentElement) {
 x1 = document.documentElement.scrollLeft || 0;
 y1 = document.documentElement.scrollTop || 0;
 }

 if (document.body) {
 x2 = document.body.scrollLeft || 0;
 y2 = document.body.scrollTop || 0;
 }

 x3 = window.scrollX || 0;
 y3 = window.scrollY || 0;

 var x = Math.max(x1, Math.max(x2, x3));
 var y = Math.max(y1, Math.max(y2, y3));

 window.scrollTo(Math.floor(x / 2), Math.floor(y / 2));

 if (x > 0 || y > 0) {
 window.setTimeout("backToTop()", 25);
 }
}