Updating Textbox?

 Hello
I have a problem when I want to update my textbox, I have a textbox called Textbox1, when I Insert data from it to database it is working well, even when I Update it WITHOUT SELECT field from database it is working well again,

but when I Select [pagename] from database then want to Update it it is not working, nothing happend and in debuging the textbox doesnt have any value. what shoud i do? the value become null?


    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Label1.Text = Request("Id").ToString()

        Dim conname As String = ConfigurationManager.ConnectionStrings("IPbrandConnectionString").ConnectionString()
        Dim con As New SqlConnection(conname)
        Dim sql As String = "SELECT [Id], [pagename] FROM [content] WHERE ([Id] = @Id)"

        Dim cmd As New SqlCommand(sql, con)
        cmd.Parameters.Add(New SqlParameter("@Id", SqlDbType.Int, 32))
        cmd.Parameters("@Id").Value = Label1.Text.ToString()
        con.Open()
        Dim reader As SqlDataReader = cmd.ExecuteReader()
        Do While reader.Read()
            TextBox1.Text = reader("pagename")
  
        Loop
        reader.Close()
        con.Close()
    End Sub

 Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim conname1 As String = ConfigurationManager.ConnectionStrings("IPbrandConnectionString").ConnectionString()
        Dim con1 As New SqlConnection(conname1)
        Dim sql1 As String = "UPDATE [content] SET [pagename] = @pagename WHERE [Id] = @Id "
        Dim cmd1 As New SqlCommand(sql1, con1)

        cmd1.Parameters.Add(New SqlParameter("@Id", SqlDbType.Int, 32))
        cmd1.Parameters("@Id").Value = Label1.Text.ToString()
        cmd1.Parameters.Add(New SqlParameter("@pagename", SqlDbType.VarChar, 50))
        cmd1.Parameters("@pagename").Value = TextBox1.Text.ToString()
        cmd1.UpdatedRowSource = UpdateRowSource.OutputParameters

        Try
            con1.Open()

            cmd1.ExecuteNonQuery()

        Catch err As SqlException
            Throw New ApplicationException("Data error.")
        Finally
            con1.Close()
        End Try

        Server.Transfer("main.aspx")