Ciao a tutti.

Con questo riempio il mio radiobuttonlist:
codice:
<%@ Page Language="VB" Debug="true" %>
<%@Import Namespace="System.Data"%>
<%@Import Namespace="System.Data.OleDb"%>

<script runat=server>
    Sub Page_Load(ByVal obj As Object, ByVal e As EventArgs)
        cartoline2.Attributes.Add("style", "display: none;")
        cartoline1.Attributes.Add("style", "display: "";")
        
        Dim cmd As OleDbCommand
        Dim rdr As OleDbDataReader

        Dim cn As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;" & _
                  "DATA Source=C:\Documents and Settings\davidee\Documenti\Visual Studio 2005\mdb-database\cartoline.mdb;")
        cn.Open()
        Dim sql As String = "SELECT DISTINCT genereID FROM cartoline"

        cmd = New OleDbCommand(sql, cn)
        rdr = cmd.ExecuteReader()
        
        RadioButtonList1.DataSource = rdr
        RadioButtonList1.DataBind()
        
        cn.Close()
    End Sub
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con questo vorrei recuperare il valore selezionato inviato tramite form:
codice:
.
.
.
    Sub Visualizza(ByVal obj As Object, ByVal e As EventArgs)
        
        If RadioButtonList1.SelectedValue = "" Then
            Label1.Text = "seleziona un genere"
            Label2.Text = RadioButtonList1.SelectedValue
        Else
            cartoline1.Attributes.Add("style", "display: none;")
            cartoline2.Attributes.Add("style", "display: "";")
            
            Dim cmd As OleDbCommand
            Dim rdr As OleDbDataReader
            Dim cn As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;" & _
                      "DATA Source=C:\Documents and Settings\davidee\Documenti\Visual Studio 2005\mdb-database\cartoline.mdb;")

            cn.Open()
            Dim sql As String = "SELECT NomeImm FROM cartoline WHERE genereId = " & RadioButtonList1.SelectedValue
            cmd = New OleDbCommand(sql, cn)
            rdr = cmd.ExecuteReader()
            
            Repeater1.DataSource = rdr
            Repeater1.DataBind()
            cn.Close()
        End If
    
    End Sub
L'html è:
codice:
<html>
<head>
</head>
<body>
    <form id="Form1" runat="server">
    <div id="cartoline1" runat="server">
    <asp:RadioButtonList id="RadioButtonList1" datatextfield="genereID" runat="server" RepeatLayout="Flow" DataValueField="genereID"></asp:RadioButtonList>

    <asp:Button ID="Button1" onclick="Visualizza" runat="server" Text="Invia" />

        <asp:Label ID="Label1" runat="server"></asp:Label>
        <asp:Label ID="Label2" runat="server"></asp:Label>
    </div>
    </form>
    <div id="cartoline2" runat="server">
    <asp:Repeater id="Repeater1" runat="server">
      <ItemTemplate>
      .
      .
      .
      </ItemTemplate>
    </asp:Repeater>
    </div>
</body>
</html>
Per quale motivo all'invio del form ricevo "seleziona un genere" (vedere parte in rosso del codice).
Grazie