diff --git a/YACOSCore/ejbModule/org/yacos/core/users/IUserManager.java b/YACOSCore/ejbModule/org/yacos/core/users/IUserManager.java
index 0f88886..8548a17 100644
--- a/YACOSCore/ejbModule/org/yacos/core/users/IUserManager.java
+++ b/YACOSCore/ejbModule/org/yacos/core/users/IUserManager.java
@@ -29,8 +29,8 @@ public interface IUserManager {
 
 	// Lists methods
 	public List<User> getUsers();
-	public List<User> getUsers(Conference conf);
-	public List<User> getUsers(int conf_id,Role.RoleType type);
+	public List<User> getUsers(int conf_id);
+	public List<User> getUsers(int conf_id, Role.RoleType type);
 	public List<User> getRefereesOFPCMemberForArticle(String PCMemberLogin, Integer articleId);
 	public List<User> getPCMemberForArticle(Integer articleId);
 	
diff --git a/YACOSCore/ejbModule/org/yacos/core/users/UserManagerBean.java b/YACOSCore/ejbModule/org/yacos/core/users/UserManagerBean.java
index 6feaaa4..7208112 100644
--- a/YACOSCore/ejbModule/org/yacos/core/users/UserManagerBean.java
+++ b/YACOSCore/ejbModule/org/yacos/core/users/UserManagerBean.java
@@ -95,9 +95,12 @@ public class UserManagerBean implements IUserManager{
 		return (this.getUser(login)!= null); 
 	}
 
-	public List<User> getUsers(Conference conf) {
-		// TODO Auto-generated method stub
-		return null;
+	@SuppressWarnings("unchecked")
+	public List<User> getUsers(int conf_id) {
+		Query query = em.createQuery("select user from Role role where role.conference = ?");
+		Conference conference = em.find(Conference.class, conf_id);
+		query.setParameter(1, conference);
+		return query.getResultList();
 	}
 
 	@SuppressWarnings("unchecked")
@@ -109,7 +112,6 @@ public class UserManagerBean implements IUserManager{
 		return query.getResultList();
 	}
 	
-	 
 	@SuppressWarnings("unchecked")
 	public List<User> getPCMemberForArticle(Integer articleId){
 		//select p from Paper p join p.referees r where r.login=:aLogin and p.conference=:aConf