[DotNetDevelopment] CascadingDropDown postback

[shree]

Hello folks,

          I have two drop downs one with state names and other with
city names
depending upon state name I am loding city names.
Here I am using CascadingDropDown extender to load state and city
names.

here is my code

<td>
  <asp:UpdatePanel ID="UpdatePanel1" runat="server"
UpdateMode="Conditional">
        <ContentTemplate>
        <span class="NormalText"> City, state, and ZIP Code</span>
<br />
        <span style="font-size: 8pt;" class="Asterisk">*</span>
        <asp:DropDownList ID="ddlState" runat="server">
        </asp:DropDownList>
        <ajaxtoolkit:CascadingDropDown ID="CascadingDropDown1"
runat="server" Category="State"
                ServicePath="~/WebService.asmx"
ServiceMethod="GetDropDownState"
                TargetControlID="ddlState" PromptText="Select State"
LoadingText="[Loading state...]">
        </ajaxtoolkit:CascadingDropDown>
        <asp:DropDownList ID="ddlCity" AutoPostBack="true"
runat="server" OnSelectedIndexChanged="ddlCity_SelectedIndexChanged">
        </asp:DropDownList>
        <ajaxtoolkit:CascadingDropDown ID="CascadingDropDown2"
runat="server" Category="City"
                ServicePath="~/WebService.asmx"
ServiceMethod="GetDropDownCity"
                TargetControlID="ddlCity" ParentControlID="ddlState"
                PromptText="Select City" LoadingText="[Loading
city...]">
        </ajaxtoolkit:CascadingDropDown>

        <asp:TextBox ID="txtZip" MaxLength="5"
OnTextChanged="txtZIP_TextChanged" AutoPostBack="true"
runat="server"></asp:TextBox>
        <asp:RequiredFieldValidator ID="RequiredFieldValidator5"
runat="server" ControlToValidate="txtZip" ErrorMessage="Enter ZIP
Code" ValidationGroup="w9Error" Display="None"></
asp:RequiredFieldValidator>

        <ajaxtoolkit:ValidatorCalloutExtender
TargetControlID="RequiredFieldValidator5"
ID="ValidatorCalloutExtender6" runat="server">
        </ajaxtoolkit:ValidatorCalloutExtender>

        <ajaxtoolkit:FilteredTextBoxExtender ID="FilteredTextBoxExtender4"
TargetControlID="txtZip"
                FilterType="Numbers" runat="server">
        </ajaxtoolkit:FilteredTextBoxExtender>
        <ajaxtoolkit:AutoCompleteExtender ID="AutoCompleteExtender3"
TargetControlID="txtZip"
                ServiceMethod="GetZip" MinimumPrefixLength="1" ServicePath="~/
WebService.asmx" runat="server"
                CompletionListCssClass="completionList"
 
CompletionListHighlightedItemCssClass="itemHighlighted"
                CompletionListItemCssClass="listItem">
        </ajaxtoolkit:AutoCompleteExtender>
        </ContentTemplate>
        <Triggers>
                <asp:AsyncPostBackTrigger ControlID="ddlCity"
EventName="SelectedIndexChanged" />
       </Triggers>
       </asp:UpdatePanel>
</td>


here autopostback of ddlCity is not working