// tooltip widget
function positionTooltip(event, element){
  var x = Event.pointerX(event);
  var y = Event.pointerY(event);
  element.style.top = y + 5;
  element.style.left = x - 40;
}

function showTooltip(event, element) {
positionTooltip(event, element);
element.show();
}

function hideTooltip(event, element) {
positionTooltip(event, element);
element.hide();
}

function toggleTooltip(event, element) {
    var x = Event.pointerX(event);
    var y = Event.pointerY(event);
    element.style.top = y + 5;
    element.style.left = x - 40;
    element.toggle();
}