function sortSessions(by){
 document.getElementById("filter_loader").style.display = "inline-block";
 WL_LoadPageFeedback("/data/sessionSort.php?by="+by, "screen", function(){
  document.getElementById("filter_loader").style.display = "none";
 });
}
function showLabel(id){
 document.getElementById("L"+id).style.visibility = "visible";
}
function hideLabel(id){
 document.getElementById("L"+id).style.visibility = "hidden";
}