diff --git a/YACOSWeb/WebContent/WEB-INF/classes/messages.properties b/YACOSWeb/WebContent/WEB-INF/classes/messages.properties
index d57837e..9e12f3c 100644
--- a/YACOSWeb/WebContent/WEB-INF/classes/messages.properties
+++ b/YACOSWeb/WebContent/WEB-INF/classes/messages.properties
@@ -79,6 +79,13 @@ form.register.error.passwordEmpty=The password can't be empty
 form.register.error.alreadyExists=A user with this login already exists. Please check you haven't already registered or change your login. 
 
 
+###################
+# MESSAGE ERROR
+message.error.noconferenceforthisid=This conference doesn't exist. Pease try again
+message.error.noconferenceid=No conference selectionned
+message.error.conferenceerror=Error. Try again.
+
+
 submission.title=Article's submission
 
 form.submission.article.title=Article's title
diff --git a/YACOSWeb/WebContent/WEB-INF/decorators/headerchoose.jsp b/YACOSWeb/WebContent/WEB-INF/decorators/headerchoose.jsp
index a71e47e..43d672e 100644
--- a/YACOSWeb/WebContent/WEB-INF/decorators/headerchoose.jsp
+++ b/YACOSWeb/WebContent/WEB-INF/decorators/headerchoose.jsp
@@ -13,7 +13,7 @@
 			<div id="bar">
 			<div id="rightchoice">
 			
-						<c:choose>
+		<c:choose>
 			<c:when test="${currentConferenceId != null}">
 				La conférence courante est :<br />
 				<span class="currentConferenceTitle">${currentConference.title}</span>
diff --git a/YACOSWeb/WebContent/WEB-INF/jsp/listConference.jsp b/YACOSWeb/WebContent/WEB-INF/jsp/listConference.jsp
index c2360a7..a3bea73 100644
--- a/YACOSWeb/WebContent/WEB-INF/jsp/listConference.jsp
+++ b/YACOSWeb/WebContent/WEB-INF/jsp/listConference.jsp
@@ -6,12 +6,23 @@
 
 <h2 align="center">Choose a conference</h2>
 
+	<c:if test="${errorMessage != null}">
+		<span class="formError">
+		<c:choose>
+			<c:when test="${errorMessage == 1}"><fmt:message key="message.error.noconferenceforthisid" /></c:when>
+			<c:when test="${errorMessage == 2}"><fmt:message key="message.error.noconferenceid" /></c:when>
+			<c:otherwise><fmt:message key="message.error.conferenceerror" /></c:otherwise>
+		</c:choose>
+		</span><br />
+	</c:if>
+
+
 	Choix de la conference	<br /><br />	
 	
-	<c:if test="${idCurrentConference!=null}">
-		La conférence courante est : ${idCurrentConference}.<br /><br />
+	<c:if test="${currentConferenceId!=null}">
+		La conférence courante est : ${currentConference.title}.<br /><br />
 	</c:if>
-	<c:if test="${idCurrentConference==null}">
+	<c:if test="${currentConferenceId==null}">
 		Il n'y a pas de conférence sélectionné.<br /><br />
 	</c:if>
 	
diff --git a/YACOSWeb/WebContent/WEB-INF/yacos-servlet.xml b/YACOSWeb/WebContent/WEB-INF/yacos-servlet.xml
index 55e72bc..bd5c3f6 100644
--- a/YACOSWeb/WebContent/WEB-INF/yacos-servlet.xml
+++ b/YACOSWeb/WebContent/WEB-INF/yacos-servlet.xml
@@ -209,7 +209,8 @@
    
 	<!-- Get chosen conference in session context -->
 	<bean id="ChooseConferenceController"
-		class="org.yacos.web.system.controller.ChooseConferenceController">
+		class="org.yacos.web.system.controller.ChooseConferenceController">
+		<property name="conferenceManager" ref="conferenceManager" />
 	</bean>
 
 
diff --git a/YACOSWeb/src/org/yacos/web/system/controller/ChooseConferenceController.java b/YACOSWeb/src/org/yacos/web/system/controller/ChooseConferenceController.java
index 0ba747c..ef5d712 100644
--- a/YACOSWeb/src/org/yacos/web/system/controller/ChooseConferenceController.java
+++ b/YACOSWeb/src/org/yacos/web/system/controller/ChooseConferenceController.java
@@ -1,22 +1,64 @@
 package org.yacos.web.system.controller;
 
+import java.util.HashMap;
+import java.util.Map;
+
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import org.springframework.web.servlet.ModelAndView;
 import org.springframework.web.servlet.mvc.Controller;
+import org.springframework.web.servlet.view.RedirectView;
+import org.yacos.core.conferences.IConferenceManager;
 import org.yacos.web.system.session.SessionService;
 
 public class ChooseConferenceController implements Controller {
 	
+	private IConferenceManager conferenceManager;
+
+	public IConferenceManager getConferenceManager() {
+		return conferenceManager;
+	}
+	public void setConferenceManager(IConferenceManager conferenceManager) {
+		this.conferenceManager = conferenceManager;
+	}
+	
 	public ModelAndView handleRequest(HttpServletRequest request,
 			HttpServletResponse response) throws Exception {
 
-		// get IDConf
-		int idConf = Integer.parseInt(request.getParameter("idConf")); 
+		Map<String, Object> model = new HashMap<String, Object>();
 		
-		// Set idConf in session context
-		SessionService.getInstance().setCurrentConferenceId(idConf);
+		// get IDConf if exist
+		if (request.getParameter("idConf") != null)
+		{
+			try
+			{
+				int idConf = Integer.parseInt(request.getParameter("idConf"));
+				
+				if(conferenceManager.exists(idConf))
+				{
+					// Set idConf in session context
+					SessionService.getInstance().setCurrentConferenceId(idConf);
+					
+					return new ModelAndView("main");
+				}
+				else
+				{
+					model.put("error", "1");
+					return new ModelAndView(new RedirectView("listConference.htm"), model);
+				}
+			}
+			catch(NumberFormatException e)
+			{
+				model.put("error", "3");
+				return new ModelAndView(new RedirectView("listConference.htm"), model);
+			}
+		
+		}
+		else
+		{
+			model.put("error", "2");
+			return new ModelAndView(new RedirectView("listConference.htm"), model);
+		}
 
-		return new ModelAndView("main"); 
 	}
 }
diff --git a/YACOSWeb/src/org/yacos/web/system/controller/ListConferenceController.java b/YACOSWeb/src/org/yacos/web/system/controller/ListConferenceController.java
index 433059f..473fffa 100644
--- a/YACOSWeb/src/org/yacos/web/system/controller/ListConferenceController.java
+++ b/YACOSWeb/src/org/yacos/web/system/controller/ListConferenceController.java
@@ -39,7 +39,15 @@ public class ListConferenceController implements Controller{
 	// List all conference
 	Map<String, Object> model = new HashMap<String, Object>();
 	model.put("listConference", conferenceManager.getConferences());
-
+	
+	// Error choose conference
+	String msgCode = request.getParameter("error");
+	if (msgCode != null)
+	{
+		model.put("errorMessage", msgCode);
+	}
+	
+	
 	return new ModelAndView("listConference", model);
 	}