private void dgvEmployee_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
    try
    {
        if (e.ColumnIndex == 6)
        {
            string Task = dgvEmployee.Rows[e.RowIndex].Cells[6].Value.ToString();
            if ( Task == "Delete")
            {
                if (MessageBox.Show("Are you sure to delete?", "Deleting...", MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)
                {
                    int rowIndex = e.RowIndex;
                    dgvEmployee.Rows.RemoveAt(rowIndex);
                    dataset.Tables["Employees"].Rows[rowIndex].Delete();
                    sqlAdapter.Update(dataset, "Employees");
                }
            }
            else if(Task == "Insert")
            {
                int row = dgvEmployee.Rows.Count - 2;
                DataRow dr = dataset.Tables["Employees"].NewRow();
                dr["LastName"] = dgvEmployee.Rows[row].Cells["LastName"].Value;
                dr["FirstName"] = dgvEmployee.Rows[row].Cells["FirstName"].Value;
                dr["Title"] = dgvEmployee.Rows[row].Cells["Title"].Value;
                dr["HireDate"] = dgvEmployee.Rows[row].Cells["HireDate"].Value;
                dr["PostalCode"] = dgvEmployee.Rows[row].Cells["PostalCode"].Value;

                dataset.Tables["Employees"].Rows.Add(dr);
                dataset.Tables["Employees"].Rows.RemoveAt(dataset.Tables["Employees"].Rows.Count -1);
                dgvEmployee.Rows.RemoveAt(dgvEmployee.Rows.Count - 2);
                dgvEmployee.Rows[e.RowIndex].Cells[6].Value = "Delete";
                sqlAdapter.Update(dataset, "Employees");
            }
            else if (Task == "Update")
            {
                int r = e.RowIndex;
                dataset.Tables["Employees"].Rows[r]["LastName"] = dgvEmployee.Rows[r].Cells["LastName"].Value;
                dataset.Tables["Employees"].Rows[r]["FirstName"] = dgvEmployee.Rows[r].Cells["FirstName"].Value;
                dataset.Tables["Employees"].Rows[r]["Title"] = dgvEmployee.Rows[r].Cells["Title"].Value;
                dataset.Tables["Employees"].Rows[r]["HireDate"] = dgvEmployee.Rows[r].Cells["HireDate"].Value;
                dataset.Tables["Employees"].Rows[r]["PostalCode"] = dgvEmployee.Rows[r].Cells["PostalCode"].Value;
                sqlAdapter.Update(dataset, "Employees");
                dgvEmployee.Rows[e.RowIndex].Cells[6].Value = "Delete";
            }
        }
    }
    catch (Exception ex) {  }