private void btnSave_Click(object sender, EventArgs e)
        {
            try
            {
                DialogResult dialogResult = MessageBox.Show("SAVE DATA? \nMAKE SURE ALL THE FORM FIELDS FILLED CORRECTLY", "DATA ENTRY", MessageBoxButtons.YesNo, MessageBoxIcon.Information);
                if (dialogResult == DialogResult.Yes)
                {
                    if (tbContractNumber.Text == "" || tbContractName.Text == "" || tbContractDescription.Text == "" || cbTime.SelectedIndex == -1 || tbContractInfo.Text == "")
                    {
                        MessageBox.Show("FORM FIELD(S) CAN NOT BE LEFT EMPTY. PLEASE COMPLETE THE FORM TO SAVE DATA", "DATA ENTRY ERROR", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                        tbContractNumber.Focus();
                    }
                    else
                    {
                        string ContractNumber = tbContractNumber.Text;
                        string ContractName = tbContractName.Text;
                        string ContractDescription = tbContractDescription.Text;
                        string ContractTimePeriod = cbTime.Text;
                        string ContractStartDate = dtpStartDate.Text;
                        string ContractEndDate = dtpEndDate.Text;
                        string ContractInfo = tbContractInfo.Text;
                        string EmployeeNIP = lblUser.Text;

                        Admin Save = new Admin();
                        Save.AddContract(ContractNumber, ContractName, ContractDescription, ContractTimePeriod, ContractStartDate, ContractEndDate, ContractInfo, EmployeeNIP);

                        MessageBox.Show("DATA SAVED", "ENTRY DATA SUCCESSFUL", MessageBoxButtons.OK, MessageBoxIcon.Information);

                        RefreshDG();

                        tbContractNumber.Clear();
                        tbContractName.Clear();
                        tbContractDescription.Clear();
                        cbTime.Text = "-----SELECT TIME-----";
                        dtpStartDate.Text = DateTime.Today.ToShortDateString();
                        dtpEndDate.Text = DateTime.Today.ToShortDateString();
                        dtpUpdateContractStartDate.Text = DateTime.Today.ToShortDateString();
                        dtpUpdateContractEndDate.Text = DateTime.Today.ToShortDateString();
                        tbContractInfo.Clear();
                    }
                }
            }
            catch (SqlException)
            {
                MessageBox.Show("MICROSOFT SQL SERVER DATABASE ERROR!", "ERROR OCCURS", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            catch (InvalidOperationException)
            {
                MessageBox.Show("INVALID OPERATION!", "ERROR OCCURS", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString(), "ERROR OCCURS", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }