Correction d'un bug

YACOSCore/ejbModule/org/yacos/core/evaluation/EvaluationManagerBean.java

@@ -195,8 +195,14 @@ public class EvaluationManagerBean implements IEvaluationManager {
 		Query q = em.createQuery("from Report r where article_id= ? and referee_id= ?");
 		q.setParameter(1, articleId);
 		q.setParameter(2, refereeLogin);
+		
+		try {
 			return (Report) q.getSingleResult();
 		}
+		catch (javax.persistence.NoResultException e) {
+			return null;
+		}
+	}
 
 	@SuppressWarnings("unchecked")
 	public List<Report> getReportsForArticle(int articleId) {