GridView Updating event

Private Sub GridView1_RowUpdating(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewUpdateEventArgs) Handles GridView1.RowUpdating
    Dim con As New SqlConnection(ConnectionStrings("Test").ToString)
    Try
        Dim row = GridView1.Rows(e.RowIndex)
        Dim tran As SqlTransaction
        Dim da As New SqlDataAdapter
        Dim strENo, strEName, strDob, strSalary, strDNo As String
        strENo = (CType((row.Cells(0).Controls(0)), TextBox)).Text
        strEName = (CType((row.Cells(1).Controls(0)), TextBox)).Text
        strDob = (CType((row.Cells(2).Controls(0)), TextBox)).Text
        strSalary = (CType((row.Cells(3).Controls(0)), TextBox)).Text
        strDNo = (CType((row.Cells(4).Controls(0)), TextBox)).Text
        If con.State = ConnectionState.Closed Then con.Open()
        tran = con.BeginTransaction
        Dim comUpt As New SqlCommand("SP_UPDATE_EMP", con)
        comUpt.CommandType = CommandType.StoredProcedure
        comUpt.Parameters.Add(New SqlParameter("@Emp_no", SqlDbType.Char, 10)).Value = strENo
        comUpt.Parameters.Add(New SqlParameter("@Emp_Name", SqlDbType.VarChar, 50)).Value = strEName
        comUpt.Parameters.Add(New SqlParameter("@DOB", SqlDbType.DateTime, 8)).Value = strDob
        comUpt.Parameters.Add(New SqlParameter("@Salary", SqlDbType.Decimal, 17)).Value = strSalary
        comUpt.Parameters.Add(New SqlParameter("@D_No", SqlDbType.SmallInt, 2)).Value = strDNo
        comUpt.Parameters.Add(New SqlParameter("@ErrNo", SqlDbType.SmallInt)).Direction = ParameterDirection.Output
        comUpt.Transaction = tran
        da.UpdateCommand = comUpt
        da.Update(ds, "emp")
        tran.Commit()
        LoadGrid()
    Catch ex As Exception
    Finally
        If con.State = ConnectionState.Open Then con.Close()
    End Try
End Sub