Probleme simple et evident en php ( 1 ligne de code )

		if($_SESSION['ndc'] == $sujetInfos['autor'] OR $_SESSION['rang'] == "moderateur" OR $_SESSION['rang'] == "administrateur")
		{
			echo '<br /><br /><a href="edit.php?title='. $sujetInfos['title'] .'">Modifier</a>';
			echo '<br /><a href="../">Retour</a>';
			?>
			<form method="post" action="">
				<input type="submit" class="btn btn-primary" value="supprimer le sujet" name="delete_sujet">
			</form>
			<?php
			if(isset($_POST['delete_sujet']))
			{
				$deleteSujet = $bdd->prepare(" DELETE FROM sujets WHERE title = ? ");
				$deleteSujet->execute(array($_GET['title']));
				header('refresh:0');
			}
		}