Problem in dropdown inside updatepanel

[Guvera]

Hi,

I am using Asp.Net 3.5. I am having two problems in dropdown inside the update panel. I have two drop down list. First dropdown i loaded the data from db. Its working fine. Once i changed the data using SelectedIndexChange event it's firing first time(i put AutoPostback="true") if i click multiple times for multiple data it's not fired. If changed the value i bind the data to another dropdown list. But it is not binding. My control is inside the update panel. What is the problem? i came across multiple site and try it.But no use? Its very urgent. I put the code here.

//////////// HTML Source Code/////////////////////////

<form id="MAppNHSTDAfrm" runat="server">
    <telerik:RadScriptManager ID="RdScptMgrMAppNHSTDAfrm" EnablePartialRendering="true"
        AsyncPostBackTimeout="36000" runat="server">
    </telerik:RadScriptManager>
    <telerik:RadStyleSheetManager ID="RdStyMgrMAppNHSTDAfrm" EnableStyleSheetCombine="true"
        runat="server">
    </telerik:RadStyleSheetManager>
    <div class="contentcontainer">
        <fieldset style="width: 98&#37;; height: 93%">
            <asp:UpdatePanel ID="uPnlProgramDetails" runat="server" UpdateMode="Conditional">
                <ContentTemplate>
                    <table border="0" cellpadding="3" cellspacing="2" style="width: 100%;">
                        <tr>
                           <td id="Td7" runat="server">
                                                Branch :&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
                                               
                                               <asp:DropDownList ID="uxBranch" runat="server"  AutoPostBack = "true"
                                                    onselectedindexchanged="uxBranch_SelectedIndexChanged">
                                               </asp:DropDownList>
                                            </td>
                                            
                                            <td id="Td8" runat="server" class="datafield">
                                            Trust :&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
                                            
                                            <asp:DropDownList ID="uxTrust" runat="server">
                                            </asp:DropDownList>
                                            </td>
</tr>
</table>
  </ContentTemplate>
                <%--<Triggers>
              <%--<asp:AsyncPostBackTrigger ControlID="TypeOfApplicationDropDown" /> --%>
              <asp:AsyncPostBackTrigger ControlID="uxBranch" EventName="SelectedIndexChanged" />
            </Triggers>--%>
            </asp:UpdatePanel>
        </fieldset>
    </div>
    </form>

///////Code behind///////////////////

protected override void Page_Load(object sender, EventArgs e)
        {
           if (!Page.IsPostBack)
            {
                    FillDropDown();
            }
        }
  protected void FillDropDown()
        {
            FillForBranch();
         }
//Fill data for first drop down when page load

           protected void FillForBranch()
        {
            try
            {
                ResultBE result;
                DataTable lookUpTable = new DataTable();
                lookUpReference = new LovValueBLL();
                lookUpTable = lookUpReference.GetLovValue(27, "%", out result);
                uxBranch.DataTextField = "ValueDesc";
                uxBranch.DataValueField = "ID";
                uxBranch.DataSource = lookUpTable;
                uxBranch.DataBind();
                AddSelect(uxBranch);
                //uxBranch.SelectedIndex = 0;
            }
            catch (Exception ex)
            {
                ex.ToString();
            }
        }

// select changed the value from the first dropdown and load in other drop down
protected void uxBranch_SelectedIndexChanged(object sender, EventArgs e)
            {
                if (uxBranch.SelectedValue == "1738")
                {
                    FillForBranchAdult();
                 }
                if (uxBranch.SelectedValue == "1739")
                {
                    FillForBranchChild();
                }
                if (uxBranch.SelectedValue == "1740")
                {
                    FillForBranchMentalHealth();
                }
            }

  protected void FillForBranchAdult()
        {
            try
            {
                ResultBE result;
                DataTable lookUpTable = new DataTable();
                lookUpReference = new LovValueBLL();
                lookUpTable = lookUpReference.GetLovValue(24, "%", out result);
                uxTrust.DataTextField = "ValueDesc";
                uxTrust.DataValueField = "ID";
                uxTrust.DataSource = lookUpTable;
                uxTrust.DataBind();
                //uPnlProgramDetails.Update();
                AddSelect(uxTrust);
                
            }
            catch (Exception ex)
            {
                ex.ToString();
            }
        }

Hope your's reply.

Thanks