private void btnSearch_Click(object sender, EventArgs e)
{
DateTime startDate = calStartDueDate.Value;
DateTime endDate = calEndDueDate.Value;
List <Invoice> invoiceList = BLInvoice.GetInvoiceByDate(APCContext, startDate, endDate, cbPaid.Checked);
dgPaymentFromCustomer.DataSource = convertListToDataTable(invoiceList);
}
