function getAlertSelector(selector){
    return $.data(document.body, 'alertSelector');
}
function setAlertSelector(selector){
    $.data(document.body, 'alertSelector', selector);
}
function alertUser(text, title, onClose){
    var selector=getAlertSelector();
    if (selector){
        $(selector+' .dlg_text').html(text);
        $(selector).dialog('option', {
            _onClose: onClose,
            title: title ? title : 'Error'
        }).dialog('open');
        return;
    }
    alert(text);
    if (onClose)
        onClose();
}