Locate HTML Element when it does not have the runat="server" attribute
<p>I have an ASP.NET C# website and I am attempting to retrieve the inner html from a HTML in my page when a button is clicked.</p>

<p><strong>My Problem:</strong> I use the function FindControl() but it returns null when it should find the element. Why is this happening, what am I doing wrong?</p>

<p>My HTML page:</p>

<pre><code>&lt;%@ Page Title="test" Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true"
    CodeBehind="test.aspx.cs" Inherits="test" %&gt;

&lt;asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="ActualContent"&gt;
    &lt;div class="regMainContainer mainContainer container"&gt;
            &lt;!-- Attempting to get the below div --&gt;
            &lt;!-- Knowtice it does not have runat="server", 
                 I would prefer not to do that if I dont need to --&gt;
            &lt;div id="courseDiv" class="courseContainer"&gt;
            &lt;/div&gt;
    &lt;/div&gt;
&lt;/asp:content&gt;
</code></pre>

<p>My Code that executes when a button is clicked(inside test.aspx.cs file:</p>

<pre><code>HtmlGenericControl d = (HtmlGenericControl)FindControl("courseDiv");
</code></pre>
