Set the style of a parent DIV to a usercontrol - asp.net

Question

I have a dynamically named DIV in a GridView which contains a user control with a dynamically assigned Parent_ID. The javascript is used to show or hide the DIV. I'll show you two examples of different rows without the ASP code.
Row 1 showing for Order # 123456:
<a href="<%#"javascript:collapseExpand('Order_Notes_Panel123456');" %>" >+</a>
<div id='Order_Notes_Panel123456' style="display:none;">
<uc:Comments_Control id="Comments_Control_ID" runat="server" Parent_ID='123456'/>
</div>
Row 2 showing for Order # 678901:
<a href="<%#"javascript:collapseExpand('Order_Notes_Panel678901');" %>" >+</a>
<div id='Order_Notes_Panel678901' style="display:none;">
<uc:Comments_Control id="Comments_Control_ID" runat="server" Parent_ID='678901'/>
</div>
The good news is that the user control binds and works perfectly. The javascript shows (sets the style to "display:block;") and hides (style set to "display:none;") the appropriate DIV each time the '+' is clicked.
Here is my problem: there is a 'Reply' link in the user control that, when clicked, does a post-back and puts the control into Edit mode. When I employ this user control on another page without a containing DIV, you won't notice a thing. However, when the 'Reply' does its post-back, the containing DIV reverts back to style="display:none;".
Can you provide a recommendation how to set the parent DIV's style to "display:block;" while a user is obviously working with it? I would imagine the appropriate code would go in the code behind of the user control when it goes into Edit mode.
Thanks,
Rob
Update: I recognize that there is no runat=server in my DIV. Since I'm trying to establish a dynamic ID for each, I get an error if I try to use the runat. That is probably the reason why I can't reach it from code behind...

Answer 1

I am very happy of myself... (see the YouTube video for this phrase, you'll be glad you did.)
In summary, this is what I added:
1. New Javascript function to add the name of the target DIV to a hidden field (The "collapseExpand" function is in the Site.Master. I couldn't put "load_div_to_hidden" in the Site.Master since "myhiddenField" isn't set up on every page
2. New hidden field to capture the name of the target DIV
3. New Javascript function to run on window.onload, check if we've got a post-back, and then display the value from the hidden field
4. Adding second Javascript call from the href in the link
Below are the new snippets of code:
<script type="text/javascript">
function load_div_to_hidden(obj) {
var hidden = document.getElementById('<%= myhiddenField.ClientID %>');
hidden.value = obj;
}
function windowOnLoad() {
var isPostBack = (('<%= IsPostBack %>').toLowerCase() == 'true') ? true : false;
if (isPostBack == true) {
var hid_field_value = document.getElementById('<%= myhiddenField.ClientID %>').value;
var right_div = document.getElementById(hid_field_value);
right_div.style.display = "block";
}
}
window.onload = windowOnLoad;
</script>
<input type="hidden" id="myhiddenField" runat="server" value="" />
<a href="<%#"javascript:collapseExpand('Order_Notes_Panel123456'); javascript:load_div_to_hidden('Order_Notes_Panel123456');" %>" >+</a>
<div id='Order_Notes_Panel123456' style="display:none;">
<uc:Comments_Control id="Comments_Control_ID" runat="server" Parent_ID='123456'/>
</div>
Works like a charm!