FindControl always returns null

 Alright so i have problem i am problematically creating most of the content but i am not able to find any of the controls that i have just created. any help would be great.

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="QuizSys.aspx.cs" Inherits="QuizSys" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Quiz</title>
</head>
<body>
<form id= ...