function ShowHelp(txt, event) {
  if (txt == '') { return; }
var helpDiv = document.getElementById('div_Help');
helpDiv.innerHTML = txt;

var ev = event || window.event;
helpDiv.style.left = ev.pageX + 'px';
helpDiv.style.top = (ev.pageY - 10) + 'px';
helpDiv.style.display = '';
}