无法显示消息框对话框

Question

I have this code:

function delTempBill() {
    if ($('#bills_ID').val() == '') {
        popUpMessage("Error", "choose bills to delete", 2);
    } else {
        $.ajax({
            url: "DelTempBill.php",
            type: "POST",
            data: {
                draft: "ok",
                bills_ID: selectedTempId
            },
            dataType: "json",
            success: function (data2) {
                if (parseInt(data2) > 0) {
                    $("#tempBills" + selectedTempId).remove();
                    popUpMessage("Done", "Bills was Delete", 2);
                    newGrid();
                }
            }
        });
    }
}

This code is to delete bills from table, when I call this function the bill was deleted but the message cannot show.

Why ?