diff --git a/YACOSCore/ejbModule/org/yacos/core/conferences/Conference.java b/YACOSCore/ejbModule/org/yacos/core/conferences/Conference.java
index 9fc5fda..3d0f8fb 100644
--- a/YACOSCore/ejbModule/org/yacos/core/conferences/Conference.java
+++ b/YACOSCore/ejbModule/org/yacos/core/conferences/Conference.java
@@ -5,6 +5,7 @@ import java.util.ArrayList;
 import java.util.Date;
 import java.util.List;
 
+import javax.persistence.CascadeType;
 import javax.persistence.Entity;
 import javax.persistence.GeneratedValue;
 import javax.persistence.GenerationType;
@@ -13,7 +14,6 @@ import javax.persistence.OneToMany;
 import javax.persistence.Temporal;
 import javax.persistence.TemporalType;
 
-
 import org.yacos.core.article.Article;
 import org.yacos.core.evaluation.Criterion;
 import org.yacos.core.users.Role;
@@ -54,7 +54,7 @@ public class Conference implements Serializable{
 	@OneToMany(targetEntity=Article.class,mappedBy="conference")
 	private List<Article> articles;
 	
-	@OneToMany(targetEntity=Criterion.class,mappedBy="conference")
+	@OneToMany(targetEntity=Criterion.class,mappedBy="conference",cascade=CascadeType.ALL)
 	private List<Criterion> criterions;
 	
 	/*
@@ -193,12 +193,12 @@ public class Conference implements Serializable{
 	/*
 	 * criterions
 	 */
-	@OneToMany(targetEntity=Criterion.class,mappedBy="conference")
+	@OneToMany(targetEntity=Criterion.class,mappedBy="conference",cascade=CascadeType.ALL)
 	public List<Criterion> getCriterions() {
 		return criterions;
 	}
 
-	@OneToMany(targetEntity=Criterion.class,mappedBy="conference")
+	@OneToMany(targetEntity=Criterion.class,mappedBy="conference",cascade=CascadeType.ALL)
 	public void setCriterions(List<Criterion> criterions) {
 		this.criterions = criterions;
 	}
diff --git a/YACOSCore/ejbModule/org/yacos/core/conferences/ConferenceDoesntExistException.java b/YACOSCore/ejbModule/org/yacos/core/conferences/ConferenceDoesntExistException.java
deleted file mode 100644
index 2e0033f..0000000
--- a/YACOSCore/ejbModule/org/yacos/core/conferences/ConferenceDoesntExistException.java
+++ /dev/null
@@ -1,5 +0,0 @@
-package org.yacos.core.conferences;
-
-public class ConferenceDoesntExistException extends Exception {
-
-}
diff --git a/YACOSCore/ejbModule/org/yacos/core/conferences/ConferenceManagerBean.java b/YACOSCore/ejbModule/org/yacos/core/conferences/ConferenceManagerBean.java
index 35bd956..5ce0216 100644
--- a/YACOSCore/ejbModule/org/yacos/core/conferences/ConferenceManagerBean.java
+++ b/YACOSCore/ejbModule/org/yacos/core/conferences/ConferenceManagerBean.java
@@ -21,6 +21,7 @@ public class ConferenceManagerBean implements IConferenceManager {
 	public Conference addConference(String titre, String descirption, String infoComplementray, Date dataAbstract, Date dateArticle, Date dateEvaluation, Date dateStart, Date dateEnd) {
 		Conference conf = new Conference(titre, descirption, infoComplementray, dataAbstract, dateArticle, dateEvaluation, dateStart, dateEnd);
 		em.persist(conf);
+		em.flush();
 		return conf;
 	}
 
@@ -31,10 +32,12 @@ public class ConferenceManagerBean implements IConferenceManager {
 	public void remove(Integer conferenceId) {
 		Conference persistedConf = em.find(Conference.class, conferenceId);
 		em.remove(persistedConf);
+		em.flush();
 	}
 
 	public void update(Conference conf) {
 		em.merge(conf);
+		em.flush();
 	}
 
 	@SuppressWarnings("unchecked")
@@ -58,7 +61,7 @@ public class ConferenceManagerBean implements IConferenceManager {
 			
 	/* 
 	 * 
-	 * méthodes relatives aux roles
+	 * m�thodes relatives aux roles
 	 * */
 	
 	public void addRole(Role.RoleType roleType, String login, Integer confId) {
@@ -66,14 +69,17 @@ public class ConferenceManagerBean implements IConferenceManager {
 		Conference conf = em.find(Conference.class, confId);
 		Role role = new Role(roleType, user, conf);
 		em.persist(role);
+		em.flush();
 	}
 
 	public void removeRole(Role role) {
 		em.remove(role);
+		em.flush();
 	}
 
 	public void updateRole(Role role){
 		em.merge(role);
+		em.flush();
 	}
 	
 	@SuppressWarnings("unchecked")