Modal ASP.net user control - asp.net

Question

I have a web form app where a couple of user-controls have been developed and placed on a page where a customer is building an order. The user-controls are pretty extensive in what they do, causing post-backs, etc.
I'd like to display them in a modal fashion without putting them in a separate page (if possible). So therein lies my question.
Is it possible to place user-controls within divs/panels, display them modally and keep them displayed modally (even through postbacks) until the user clicks a button on the control to dismiss it?
I'm basically looking at the modal option because I need to disable the rest of the form while the user is dealing with the sections the user-control is on. So I'm looking for a best-practice approach I suppose and some nudges in the right direction for this.
Thanks!
ADDITION:
I wanted to update this with the code I wrote in hopes that it might help somebody else and also if there is a better way to implement this, then I'm all ears too.
The basics of this is that I'm passing everything back and forth between my user control and the container page through session vars. I use this to tell the container page whether or not the user control is "finished" and until the flag is set to true, the container page just keeps re-displaying the user control modally on each postback. Seems to work well so far.
Markup:
<%# Register Src="../controls/mylabel.ascx" TagName="mylabel" TagPrefix="uc1" %>
<div style="width: 100%;">
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:Button ID="ButtonAddToCart" runat="server" Text="Add to cart" OnClick="ButtonAddToCartClick" />
</div>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:Panel ID="pnlOutput" Visible="False" runat="server" Width="500px">
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</asp:Panel>
</ContentTemplate>
</asp:UpdatePanel>
<div style="visibility: hidden;">
<asp:Button ID="ButtonHidden" runat="server" Text="Button" />
</div>
<asp:Panel ID="pnlDownload" Visible="False" runat="server">
<asp:UpdatePanel ID="UpdatePanel2" runat="server">
<ContentTemplate>
<div style="width: 100%;">
<uc1:mylabel ID="mylabel1" runat="server" />
</div>
</ContentTemplate>
</asp:UpdatePanel>
</asp:Panel>
Code behind:
protected void Page_PreRender(object sender, EventArgs e)
{
InitializeControls();
}
protected void Page_Load(object sender, EventArgs e)
{
InitializeControls();
}
private void InitializeControls()
{
DisplayDownloadPanel(!SessionDownloadComplete);
if (SessionDownloadItemNumber != string.Empty)
{
Label1.Text = SessionDownloadItemNumber != "CANCEL" ? "Item ordered from control was: [" + SessionDownloadItemNumber + "]" : "Order was canceled.";
pnlOutput.Visible = true;
}
}
protected void ButtonAddToCartClick(object sender, EventArgs e)
{
bool haveWeSomeText = string.IsNullOrEmpty(TextBox1.Text) == false;
if (haveWeSomeText == true)
{
SessionDownloadComplete = false;
DisplayDownloadPanel(true);
}
}
private void DisplayDownloadPanel(bool show)
{
pnlDownload.Visible = show;
if (show == true)
{
ModalPopupExtender1.Show();
}
else
{
ModalPopupExtender1.Hide();
}
}
private string SessionDownloadItemNumber
{
get { return Session["DownloadItemNumber"] != null ? Session["DownloadItemNumber"].ToString() : string.Empty; }
}
private bool SessionDownloadComplete
{
get { return Session["DownloadComplete"] == null || Convert.ToBoolean(Session["DownloadComplete"]); }
set { Session["DownloadComplete"] = value; }
}

Answer 1

Have a look at ASP.NET Ajax Toolkit Modal popup extender

Answer 2

Take a look at the jQuery UI dialog.
It is a good solution for cross browser modal dialogs in the browser.
<script>
$(function() {
$( ".dialogClass" ).dialog({
resizable: false,
height:140,
modal: true,
buttons: {
"Delete all items": function() {
$( this ).dialog( "close" );
},
Cancel: function() {
$( this ).dialog( "close" );
}
}
});
});
</script>
There are a few initial hiccups integrating it with asp.net. But all those are very well documented here on stackover flow itself.