var alertDialog = null;
var alertX = -1; // centers dialog in window!
var alertY = -1;

function MyAppAlertSetXY(x, y) {
  // call prior to 'MyAppAlert()'
  alertX = x;
  alertY = y;
  }

function MyAppAlertXY(ev) {
  // call using 'onclick' prior to 'MyAppAlert()'
  var e = jt_fixE(ev);
  MyAppAlertSetXY(e.clientX, e.clientY + document.body.scrollTop);
  return true;
  }

function MyAppAlertInit(title, icon) {
  // 'title' and 'icon' are optional; both may be changed using 'MyAppAlert()'
  var locTitle = TitreBar;
  if (title) locTitle += " - " + title;
  if (alertDialog == null) {
    alertDialog = new jt_AppAlert(icon ? icon : jt_AppAlert.Error);
    alertDialog.setTitle(locTitle);
    }
  else {
    if (title) alertDialog.setTitle(locTitle);
    if (icon) alertDialog.setIcon(icon);
    }
  }

function MyAppAlert(msg, title, icon) {
  // 'title' and 'icon' are optional
  MyAppAlertInit(title, icon);
  alertDialog.setContent(msg);
  alertDialog.moveTo(alertX, alertY);
  alertDialog.show();
  if ((alertX == -1) || (alertY == -1)) alertDialog.moveTo(alertX, alertY);
  }