private void button1_Click(object sender, EventArgs e)
        {
            try {
                if(!sKUComboBox.Items.Contains(sKUComboBox.Text))
                    throw new ArgumentException("SKU Does Not Exist.");

                var countsTable = new InventoryDataSetTableAdapters.CountsTableAdapter();
                var count = countTextBox.Text.StartsWith("-") ? countTextBox.Text.Substring(1) : countTextBox.Text;

                countsTable.Insert(DateTime.Now, sKUComboBox.Text, int.Parse(count), !countTextBox.Text.StartsWith("-"), 1, textBox1.Text);

                DialogResult = DialogResult.OK;
            } catch (Exception ex) {
                MessageBox.Show(ex.Message, "", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
        private void RefreshCounts()
        {
            foreach (var row in itemsDataGridView.Rows.Cast<DataGridViewRow>().Where(col => col.Cells[1].Value != null)) {
                var countsTableAdapter = new InventoryDataSetTableAdapters.CountsTableAdapter();

                var dataAdd = Total(countsTableAdapter.GetData().Where(rowCount => rowCount.SKU == (string)row.Cells[1].Value && rowCount.Add));
                var dataRemove = Total(countsTableAdapter.GetData().Where(rowCount => rowCount.SKU == (string)row.Cells[1].Value && !rowCount.Add));

                row.Cells[6].Value = dataAdd - dataRemove;
            }
        }