dropdwnlist autopostback not working
<p>dropdwnlist autopostback not working 
my code as follows:</p>

<pre><code>&lt;asp:DropDownList ID="ddlState" runat="server" Width="200px" AutoPostBack="true" onselectedindexchanged="ddlState_SelectedIndexChanged" &gt;
   &lt;%--  &lt;asp:ListItem Selected="True"&gt;--Select--&lt;/asp:ListItem&gt;--%&gt;
&lt;/asp:DropDownList&gt;
</code></pre>

<p>Codebehind is:</p>

<pre><code>protected void ddlState_SelectedIndexChanged(object sender, EventArgs e)
{
    ddlDistrict.Enabled = true;
    ddlTaluka.Enabled = true;
    DataTable dtObj = new DataTable();
    using (var client = ServiceClient&lt;IPallaviAddressManager&gt;.Create("PallaviAddressManager"))
    {
        dtObj = client.Instance.GetAllStates();
    }
    var result = (from dt in dtObj.AsEnumerable()
                      where dt.Field&lt;Int64&gt;("StateID") == Convert.ToInt64(ddlState.SelectedValue)
                      select dt);
    dtObj = result.CopyToDataTable();
    ddlDistrict.DataSource = dtObj;
    ddlState.DataTextField = "Description";
    ddlState.DataValueField = "DistrictID";
}
</code></pre>

<p>Can you help?</p>
