The main question is how to update only the databound dropdownlist on the parent page, after the new value was added in a separate control, opened in a popup, using UrlUtils.PopUpUrl()?
After popup is closed the parent page is refreshed, new value appears in the list, but values entered/chosen in all other controls are lost. Is there a way to update only a specific control without refreshing the whole page?

Any help or link to topic, where this problem was already discussed, would be appreciated.

Parent page:
<%@ Control Language="vb" Inherits="testmodule.MainView" AutoEventWireup="false"
Explicit="True" CodeBehind="MainView.ascx.vb" %>

<asp:EntityDataSource ID="eds1" runat="server" ConnectionString="name=TESTEntities"
DefaultContainerName="TESTEntities" EnableFlattening="False" EntitySetName="ListItems"
Select="it.[ID], it.[Name]">

<asp:DropDownList ID="ddlList" runat="server" DataSourceID="eds1" DataTextField="Name"
DataValueField="ID">



Add new Item








Code behind:
Imports System.Web.UI
Imports System.Collections.Generic
Imports System.Reflection
Imports System.Linq

Imports DotNetNuke
Imports DotNetNuke.Services.Exceptions
Imports DotNetNuke.Services.Localization

Namespace testmodule
Partial Class MainView
Inherits Entities.Modules.PortalModuleBase

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Try
lb1.Attributes.Add("onclick", "return " & UrlUtils.PopUpUrl(NavigateURL("AddItem", "mid=" & Me.ModuleId), Me, PortalSettings, True, False))
Catch exc As Exception 'Module failed to load
ProcessModuleLoadException(Me, exc)
End Try
End Sub
End Class
End Namespace

Popup Control:
<%@ Control Language="vb" Inherits="testmodule.AddItem" AutoEventWireup="false"
Explicit="True" CodeBehind="AddItem.ascx.vb" %>





Add new item

Code behind:
Imports System.Web.UI
Imports System.Collections.Generic
Imports System.Reflection
Imports System.Linq

Imports DotNetNuke
Imports DotNetNuke.Services.Exceptions
Imports DotNetNuke.Services.Localization

Namespace testmodule
Partial Class AddItem
Inherits Entities.Modules.PortalModuleBase

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Try

Catch exc As Exception 'Module failed to load
ProcessModuleLoadException(Me, exc)
End Try
End Sub

Protected Sub lb1_Click(sender As Object, e As EventArgs) Handles lb1.Click
Dim z As New ListItems
Using cont As New TESTEntities
z.Name = tbx.Text
cont.ListItems.Add(z)
cont.SaveChanges()
End Using

End Sub
End Class
End Namespace