Dialogs in AX 2012

static void DialogBox(Args _args)
{
    Dialog dialog       = new Dialog("Update quantity ");
    DialogGroup         dialogGroup;
    DialogField         dialogField;
    InventQty           physicalScannedQuantity;
    dialogGroup     = dialog.addGroup('Update');
    dialogField     = dialog.addField(extendedTypeStr(InventQty));
    if (dialog.run())
    {
        physicalScannedQuantity = dialogField.Value();
    }

}