PHP - Interacción entre div y php?

<?php

if(isset($_GET['var']) && !empty($_GET['var'])){

	if ($_GET['var'] == 'yes'){

		$con = mysqli_connect('localhost','db_user','db_pass','dn_name');

		$query = "SELECT campo FROM tabla";

		$run = mysqli_query($con,$query);

		while ($row = mysqli_fetch_array($run,MYSQLI_BOTH)){

			$vals[] = $row;

		}

	}

}

?>

<a href="<?php echo $_SERVER['PHP_SELF']?>?var=yes">Llamar datos!</a>

<div id="result">

	<?php

	if(isset($vals) && !empty($vals)){

		foreach ($vals as $row) {

			echo $row['campo'].'<br>';

		}

	}

	?>

</div>