// --------------------------

        private void UpdateSelectedQuantityValuesToolStripMenuItemClick(object sender, EventArgs e)
        {
            if (this.productsDataGridView.SelectedRows.Count <= 0)
            {
                return;
            }

            DataGridViewSelectedRowCollection dataGridViewSelectedRowCollection = this.productsDataGridView.SelectedRows;
            DataGridViewRow r = dataGridViewSelectedRowCollection[0];
            ValueSetterForm valueSetterForm = new ValueSetterForm();
            DialogResult    dr = valueSetterForm.ShowDialog(this);

            if (dr != DialogResult.OK)
            {
                return;
            }

            try
            {
                foreach (DataGridViewRow row in dataGridViewSelectedRowCollection)
                {
                    row.Cells["Quantity"].Value = Convert.ToInt32(valueSetterForm.NewValue);
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(this, string.Format("An exception did occur while updating the selected values in the data grid view.\r\n\r\nException Message:\r\n{0}", ex.Message), ex.Source);
            }
            finally
            {
                this.productsDataGridView.Update();
            }
        }
        // --------------------------

        private void UpdateSelectedDiscountValuesToolStripMenuItemClick(object sender, EventArgs e)
        {
            if (this.productsDataGridView.SelectedRows.Count <= 0)
            {
                return;
            }

            DataGridViewSelectedRowCollection dataGridViewSelectedRowCollection = this.productsDataGridView.SelectedRows;
            DataGridViewRow r = dataGridViewSelectedRowCollection[0];
            ValueSetterForm valueSetterForm = new ValueSetterForm();
            DialogResult    dr = valueSetterForm.ShowDialog(this);

            if (dr != DialogResult.OK)
            {
                return;
            }

            try
            {
                double newValue;
                double.TryParse(valueSetterForm.NewValue.ToString(), NumberStyles.Float | NumberStyles.Number | NumberStyles.Integer | NumberStyles.AllowDecimalPoint, CultureInfo.InvariantCulture, out newValue);
                foreach (DataGridViewRow row in dataGridViewSelectedRowCollection)
                {
                    row.Cells["DiscountInPercentage"].Value = newValue;
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(this, string.Format("An exception did occur while updating the selected values in the data grid view.\r\n\r\nException Message:\r\n{0}", ex.Message), ex.Source);
            }
            finally
            {
                this.productsDataGridView.Update();
            }
        }
        // --------------------------
        private void UpdateSelectedQuantityValuesToolStripMenuItemClick(object sender, EventArgs e)
        {
            if (this.productsDataGridView.SelectedRows.Count <= 0)
                return;

            DataGridViewSelectedRowCollection dataGridViewSelectedRowCollection = this.productsDataGridView.SelectedRows;
            DataGridViewRow r = dataGridViewSelectedRowCollection[0];
            ValueSetterForm valueSetterForm = new ValueSetterForm();
            DialogResult dr = valueSetterForm.ShowDialog(this);
            if (dr != DialogResult.OK)
                return;

            try
            {
                foreach (DataGridViewRow row in dataGridViewSelectedRowCollection)
                    row.Cells["Quantity"].Value = Convert.ToInt32(valueSetterForm.NewValue);
            }
            catch(Exception ex)
            {
                MessageBox.Show(this, string.Format("An exception did occur while updating the selected values in the data grid view.\r\n\r\nException Message:\r\n{0}",ex.Message), ex.Source);
            }
            finally
            {
                this.productsDataGridView.Update();
            }
        }
        // --------------------------
        private void UpdateSelectedDiscountValuesToolStripMenuItemClick(object sender, EventArgs e)
        {
            if (this.productsDataGridView.SelectedRows.Count <= 0)
                return;

            DataGridViewSelectedRowCollection dataGridViewSelectedRowCollection = this.productsDataGridView.SelectedRows;
            DataGridViewRow r = dataGridViewSelectedRowCollection[0];
            ValueSetterForm valueSetterForm = new ValueSetterForm();
            DialogResult dr = valueSetterForm.ShowDialog(this);
            if (dr != DialogResult.OK)
                return;

            try
            {
                double newValue;
                double.TryParse(valueSetterForm.NewValue.ToString(), NumberStyles.Float|NumberStyles.Number|NumberStyles.Integer|NumberStyles.AllowDecimalPoint, CultureInfo.InvariantCulture, out newValue);
                foreach (DataGridViewRow row in dataGridViewSelectedRowCollection)
                    row.Cells["DiscountInPercentage"].Value = newValue;
            }
            catch (Exception ex)
            {
                MessageBox.Show(this, string.Format("An exception did occur while updating the selected values in the data grid view.\r\n\r\nException Message:\r\n{0}", ex.Message), ex.Source);
            }
            finally
            {
                this.productsDataGridView.Update();
            }
        }