af/pages/_main_menu.php

		<nav id="main_menu">
			<div class="inner_box">
				<ul>
					<li><a href="<?=url('')?>">Home</a></li>
					<li><a href="<?=url('research')?>">Research</a></li>
					<li><a href="<?=url('cv')?>">CV</a></li>
					<li><a href="<?=url('contact')?>">Contact me</a></li>
				</ul>
			</div>
		</nav>