private void simpleButton1_Click(object sender, EventArgs e)
        {
            DataRow drv = gridviewGrvList.GetFocusedDataRow();
            if (drv["ReceiptID"]!= DBNull.Value)
            {
                int ReceiptID = Convert.ToInt32(drv["ReceiptID"]);

                MovingAverage movingAverage = new MovingAverage();
                movingAverage.DataSource = MovingAverageHistory.GetMovingAverageByReceiptID(ReceiptID);
                movingAverage.ShowPreview();
            }
        }
        private void gridGrvList_MouseClick(object sender, MouseEventArgs e)
        {
            DataRow drv = gridviewGrvList.GetFocusedDataRow();
            if (drv["ReceiptID"] != DBNull.Value)
            {
                int ReceiptID = Convert.ToInt32(drv["ReceiptID"]);

                MovingAverage movingAverage = new MovingAverage();
                movingAverage.DataSource = MovingAverageHistory.GetMovingAverageByReceiptID(ReceiptID);
                movingAverage.CreateDocument();
                PrintPreview.PrintingSystem = movingAverage.PrintingSystem;
            }
        }