Using runat="server" with HTML Elements

ASP.Net developers know that in their markup pages they can use a combination of HTML Elements and ASP.Net Controls. The syntax is mildly different but there is one major distinction:

ASP.Net Controls always include the following: runat="server"

Whereas HTML Elements do not. Or at least that's what I thought!

I have a web app that utilizes a left menu to display modules to the user:

It works great, but before the user is logged in, it makes no sense to display it. Up until now I was just hiding the menu itself. This was fine but what was left was the table column behind. This is what it looked like:

What I really needed to do was hide the "td" element that contained the menu. But since it was pure HTML, I didn't think it was possible to access it from the server-side C# code.

How wrong I was! In fact, all I needed to do was add the runat="server" parameter and voila, I could access the element from C# using the "FindControl" method.

Now the entire space devoted to the menu is hidden and it looks much better. Sure it's just a little thing but sometimes those little UI improvements are what's most important to end users.