protected void searchButton_OnClick(object sender, EventArgs e) { DateTime fromDate = Convert.ToDateTime(fromDateTextBox.Text); DateTime toDate = Convert.ToDateTime(toDateTextBox.Text); if (fromDate <= toDate) { ItemViewModels = StockOutManager.GetItemByDate(fromDate, toDate); itemsGridView.DataSource = ItemViewModels; itemsGridView.DataBind(); } else { outputLabel.Text = "From date can not be greter than To date."; } }