= 'none';}
      var show = function(element) { element.style.display = '';}
      var isHidden = function(element) { return element.style.display == 'none';}
      var isSelected = function(element) { return element.classList.contains("selected");}
      var deselect = function(element) { return element.classList.remove("selected");}
      var select = function(element) { return element.classList.add("selected");}
      var toggle = function(element) { isHidden(element) ? show(element) : hide(element);};
 