Try
            ' Takes a string from the textbox to find the records source in the database
            Dim aid As String = ArrestIDToolStripTextBox.Text
            Dim cmd As OleDbCommand = New OleDbCommand("SELECT SUM(AmountPaid) FROM tblPayment WHERE ArrestID ='" & aid & "'", con) ' SQL to pull the data from the database
            con.Open() ' open the connection to the database
            Dim amtpaid As Int32 = cmd.ExecuteScalar
            TextBox2.Text = amtpaid
            con.Close()
            Dim x1, x2 As Integer
            x1 = TextBox3.Text  ' Total Fine amount.
            x2 = TextBox2.Text  ' Total amount Paid so far.
            TextBox4.Text = Val(x1) - Val(x2) ' Subtracts the total fine amount from the amount paid to give us the total amount due.
        Catch ex As Exception
            MsgBox(ex.ToString)
        End Try