private void btnPaySupplier_Click(object sender, EventArgs e) { Boolean valid = Validation.ValidateAmount(txtAmountToPay.Text); MessageBox.Show("" + valid); if (valid) { float pay = float.Parse(txtAmountToPay.Text); float balance = float.Parse(txtBalance.Text); if (balance > 0) { if (balance >= pay) { float remainder = balance - pay; int id = Convert.ToInt16(txtSupplierId.Text); //connect to the db OracleConnection connect = new OracleConnection(DBConnect.oradb); //define Sql Command String strSQL = "UPDATE Supplier SET Balance = " + remainder + " WHERE SupplierId =" + id; //Execute Query OracleCommand cmd = new OracleCommand(strSQL, connect); connect.Open(); cmd.ExecuteNonQuery(); //Close Db connect.Close(); MessageBox.Show(pay + " has been paid off the balance"); txtSupplierId.Clear(); txtSupplierName.Clear(); txtSearchSupplier.Clear(); txtBalance.Clear(); txtAmountToPay.Clear(); grdData.DataSource = null; } else { MessageBox.Show("The amount you want to pay exceeds the balance"); } } else { MessageBox.Show("The balance is zero so Cannot be paid"); } } else { MessageBox.Show("You have not entered a correct amount into the Amount to Pay Textbox"); } }