diff --git a/YACOSCore/ejbModule/org/yacos/core/conferences/ConferenceManagerBean.java b/YACOSCore/ejbModule/org/yacos/core/conferences/ConferenceManagerBean.java
index bf2fa92..3cff72f 100644
--- a/YACOSCore/ejbModule/org/yacos/core/conferences/ConferenceManagerBean.java
+++ b/YACOSCore/ejbModule/org/yacos/core/conferences/ConferenceManagerBean.java
@@ -98,7 +98,9 @@ public class ConferenceManagerBean implements IConferenceManager {
 	} 
 
 	@SuppressWarnings("unchecked")
-	public List<Role> getRoles(User user, Conference conf) {
+	public List<Role> getRoles(String userLogin, Integer confId) {
+		User user = em.find(User.class, userLogin);
+		Conference conf = em.find(Conference.class, confId);
 		 Query query = em.createQuery("from Role role where conference = ? and user = ?");
 		 query.setParameter(1, conf);
 		 query.setParameter(2, user);	
diff --git a/YACOSCore/ejbModule/org/yacos/core/conferences/IConferenceManager.java b/YACOSCore/ejbModule/org/yacos/core/conferences/IConferenceManager.java
index 7e8d14f..7278ed5 100644
--- a/YACOSCore/ejbModule/org/yacos/core/conferences/IConferenceManager.java
+++ b/YACOSCore/ejbModule/org/yacos/core/conferences/IConferenceManager.java
@@ -33,7 +33,7 @@ public interface IConferenceManager {
 	public Role addRole(Role.RoleType roleType, String login, Integer confId);
 	public void removeRole(Role role);
 	public List<Role> getRoles(Conference conf);
-	public List<Role> getRoles(User user, Conference conf);
+	public List<Role> getRoles(String userLogin, Integer confId);
 	public void updateRole(Role role);
 	public boolean exists(Integer conferenceId);
 }
diff --git a/YACOSCore/ejbModule/org/yacos/core/users/User.java b/YACOSCore/ejbModule/org/yacos/core/users/User.java
index 422f94f..1d1f2b5 100644
--- a/YACOSCore/ejbModule/org/yacos/core/users/User.java
+++ b/YACOSCore/ejbModule/org/yacos/core/users/User.java
@@ -4,6 +4,7 @@ import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.List;
 
+import javax.persistence.CascadeType;
 import javax.persistence.CascadeType;
 import javax.persistence.Column;
 import javax.persistence.Entity;