update panel does not work - asp.net

Question

im trying to get the value of a dropdownlist and insert it into a label inside an update panel like the following:
<asp:UpdatePanel ID="udpTutorialDropDown" runat="server">
<ContentTemplate>
<asp:DropDownList ID="DropDownList1" runat="server" DataSourceID="TutorialSeries" DataTextField="SeriesName" DataValueField="VideoSeriesNameID" OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged"></asp:DropDownList><br />
<asp:SqlDataSource ID="TutorialSeries" runat="server" ConnectionString="<%$ ConnectionStrings:ApplicationServices %>" SelectCommand="ViewSeasonName" SelectCommandType="StoredProcedure"></asp:SqlDataSource>
<asp:Label ID="lblEpisode" runat="server" Text="Label"></asp:Label><br />
<asp:TextBox ID="tbxURL" runat="server"></asp:TextBox><br />
<asp:TextBox ID="tbxDiscription" runat="server"></asp:TextBox><br />
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="DropDownList1" EventName="SelectedIndexChanged" />
</Triggers>
</asp:UpdatePanel>
and in code behind i have
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
lblEpisode.Text = DropDownList1.SelectedValue.ToString();
}
but i dont know why it doesnt update the label!! the text of the label remains the same!!! can someone spot the problem??

Answer 1

You have to put drop down list into existing Update panel as well...

Answer 2

Try to remove the trigger to get something like so
<br />
<asp:SqlDataSource ID="TutorialSeries" runat="server" ConnectionString="<%$ ConnectionStrings:ApplicationServices %>" SelectCommand="ViewSeasonName" SelectCommandType="StoredProcedure"></asp:SqlDataSource>
<asp:UpdatePanel ID="udpTutorialDropDown" runat="server">
<ContentTemplate>
<asp:DropDownList ID="DropDownList1" runat="server" DataSourceID="TutorialSeries" DataTextField="SeriesName" DataValueField="VideoSeriesNameID" OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged"></asp:DropDownList>
<asp:Label ID="lblEpisode" runat="server" Text="Label"></asp:Label><br />
<asp:TextBox ID="tbxURL" runat="server"></asp:TextBox><br />
<asp:TextBox ID="tbxDiscription" runat="server"></asp:TextBox><br />
</ContentTemplate>

Answer 3

You need to call the Update() method of the update panel in your Event as shown below.
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
lblEpisode.Text = DropDownList1.SelectedValue.ToString();
udpTutorialDropDown.Update();
}
All the best!
UPDATE
You must add AutoPostBack="true" property in the drop down list. And, ignore my previous instructions. I.e. calling the Update() method of the update panel. That's required only when you have UpdateMode="Conditional"
This should work :)