Question

I have a ascx page where I am using a hidden field to store the value of a the drop down box as it is generated using a google address finder. My problem is that when I try to store the value directly in the hidden field:

hfDdlVerifyID.Value = ddlVerifySS.SelectedValue;

in the event of a button click, the value is stored but on postback is lost again. Whereas, if i try to use Scriptmanager to do it, nothing is stored.

getBuild.AppendLine("$get('" + hfDdlVerifyID.ClientID + "').value = $get('" + ddlVerifySS.ClientID + ").value;");

ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "storeHidden", getBuild.ToString(), true);
//  Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "storeHidden", getBuild.ToString(), true);
string test = hfDdlVerifyID.Value.ToString();

The ascx page is :

<asp:UpdatePanel ID = ddlUpdate runat="server">
    <ContentTemplate>
         <asp:Panel ID="pVerify" runat="server">
             <br />
             <fieldset>
                 <legend>
                     <asp:Literal ID="lVerify" runat="server" />
                 </legend>
                 <asp:CheckBox
                     ID      ="cbVerify"
                     runat   ="server"
                     Text    ="Use the value from the following list, (Uncheck to accept address as it is)."
                     Checked ="true" />
                 <br />
                 <asp:DropDownList ID="ddlVerifySS" runat="server"
                     onselectedindexchanged="ddlVerifySS_SelectIndexChange" />
                 <asp:HiddenField id="hfDdlVerifyID"
                     runat   ="server" /> 
             </fieldset>
         </asp:Panel>  
     </ContentTemplate>
 </asp:UpdatePanel>

 <padrap:Button          ID          ="bVerify"
                         runat       ="server"
                         CssClass    ="btn"
                         OnClick     ="bVerify_Click"
                         Text        ="Verify Address" />

 <asp:Button             ID          ="btnSubSite" 
                         runat       ="server" 
                         text        ="Save"
                         CssCLass    ="btn" 
                         OnClick     ="save_btn_Click_subSite" 
                         onLoad="ddlVerify_Load" />

Answer 1

You should consider using Viewstate.
Hope this helps

http://msdn.microsoft.com/en-us/library/bb386448.aspx#Y2000