protected void ButtonAddCopy_Click(object sender, EventArgs e) { int bookCode = int.Parse(TextBoxBookCode.Text.Trim()); int copyNum, sequenceNum, price; string type = TextBoxType.Text.Trim(); if (!int.TryParse(TextBoxCopyNumber.Text.Trim(), out copyNum)) { return; } else if (!int.TryParse(TextBoxSequenceNumber.Text.Trim(), out sequenceNum)) { return; } else if (!int.TryParse(TextBoxPrice.Text.Trim(), out price)) { return; } CopyDAO.InsertCopy(bookCode, copyNum, sequenceNum, type, price); GridViewCopy.DataBind(); }