How to determine usercontrol selected child
<p>I have a user control, a dropdown list, that's comprised of many component controls. 
The main HtmlInputText will post back on an enter but on loss of focus it doesn't and I need that to update other controls. 
I added an onblur function, and it gets called, but I only want to postback when the element getting focus isn't part of the user control. </p>

<p>How do I determine what is selected and if it's a child of the control? </p>

<p>Markup:</p>

<pre><code>    &lt;%@ Register Assembly="MultiDropDown" Namespace="MultiDropDownLib" TagPrefix="MultiDropDownLib" %&gt;
    &lt;asp:Content ID="HeaderContent" runat="server" ContentPlaceHolderID="HeadContent"&gt;
    &lt;/asp:Content&gt;
    &lt;asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent"&gt;
        &lt;table style="width: 328px"&gt;
            &lt;tr&gt;
                &lt;td&gt;
                    ProductClass
                &lt;/td&gt;
                &lt;td&gt;
                    &lt;MultiDropDownLib:MultiDropDown ID="MultiDropDown1" runat="server" TextBoxClass="textboxDD"
                        PostOnBlur="true" /&gt;
                &lt;/td&gt;
   ...
</code></pre>

<p>And in the control:</p>

<pre><code>if (PostOnBlur)
{
    txtItemList.Attributes.Add("onblur", string.Format("PostBack();", this.ClientID));
}
</code></pre>

<p>In the PostBack I want to determine what has focus and if it's part of the control. The original control came from: <a href="http://www.codeproject.com/Articles/219977/MultiDropDown-A-multiple-selection-Dropdown-contro/%20%22MultiDropDown" rel="nofollow">http://www.codeproject.com/Articles/219977/MultiDropDown-A-multiple-selection-Dropdown-contro</a></p>
