RadWindow for ASP.NET AJAX
Contents
RadControls for ASP.NET AJAX

You can use the window URL to pass parameters that are read on the server-side to configure the controls inside the window. For example, a common application is to send the ID of a database row to extract or edit information from a database table (such as Users, Orders, Products).

The main page which calls up the RadWindow dialog presents a grid with a link field in one column to bring up the RadWindow. When the user clicks the link, it calls openRadWindow, which constructs the URL with the arguments in the query string and calls radopen to show the details window (MyDialog.aspx):

CopyASPX (Main Page)
<script type="text/javascript">
    function OpenPositionedWindow(oButton, url, windowName)
    {
        var oWnd = window.radopen(url, windowName);
    }
    function openRadWindow(CustomerID)
    {
        var oWnd = radopen("MyDialog.aspx?CustomerID=" + CustomerID, "RadWindow1");
        oWnd.center();
    }

</script>
<asp:GridView ID="GridView1" AutoGenerateColumns="False" DataSourceID="DataSource1"
    CellPadding="0" GridLines="None" CellSpacing="0" runat="server">
    <Columns>
        <asp:BoundField DataField="CompanyName" HeaderText="Company Name" />
        <asp:BoundField DataField="Country" HeaderText="Country" />
        <asp:TemplateField HeaderText="Details">
            <ItemTemplate>
                <a href="#" onclick="openRadWindow('<%# DataBinder.Eval(Container.DataItem, "CustomerID") %>'); return false;">
                    Details</a></ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>
<asp:AccessDataSource ID="DataSource1" DataFile="~/App_Data/Nwind.mdb" runat="server"
    SelectCommand="SELECT TOP 10 [CompanyName], [CustomerID],
    [ContactName], [Country] FROM [Customers]"></asp:AccessDataSource>
<telerik:RadWindowManager ID="RadWindowManager1" Width="900px" Height="200px" runat="server">
</telerik:RadWindowManager>

The parameters that you send can be read from the Request object in the Page_Load method of the page (MyDialog.aspx) being loaded in the window: