diff --git a/WEB-INF/src/controleurs/SignUp.java b/WEB-INF/src/controleurs/SignUp.java
index 821547902a697eefd780ba0ce6848060d24fdae8..bba2c247716b9be41b112adff3d8a7edcd6592b1 100644
--- a/WEB-INF/src/controleurs/SignUp.java
+++ b/WEB-INF/src/controleurs/SignUp.java
@@ -25,18 +25,23 @@ public class SignUp extends HttpServlet {
 
         }
         else {
-            userdao.createUser(login, pwd);
-            User user = userdao.getUserByLogs(login, pwd);
-
-            if (user != null && userdao.isDatabased(user)){
-                out.println("<h1>Bienvenue " + user.getUserName() + " !</h1>");
-                req.getSession().setAttribute("user", user);
-                req.getSession().setAttribute("login", login);
-                res.sendRedirect("http://localhost:8080/s4a021-web-backend/Welcome");
-            }else{
-                out.println("<h1>Partez de chez moi ?!</h1>");
-                userdao.removeUser(user);
+            if (!userdao.userExists(login, pwd)) {
+                userdao.createUser(login, pwd);
+                User user = userdao.getUserByLogs(login, pwd);
+                if (user != null && userdao.isDatabased(user)){
+                    out.println("<h1>Bienvenue " + user.getUserName() + " !</h1>");
+                    req.getSession().setAttribute("user", user);
+                    req.getSession().setAttribute("login", login);
+                    res.sendRedirect("http://localhost:8080/s4a021-web-backend/Welcome");
+                }else{
+                    out.println("<h1>Partez de chez moi ?!</h1>");
+                    userdao.removeUser(user);
+                }
+            }
+            else {
+                out.println("<h1>You already own an account. Please login <a href=\"http://localhost:8080/s4a021-web-backend/index.html\">here</a></h1>");
             }
+
         }
     }
 }
diff --git a/WEB-INF/src/dao/UserDAO.java b/WEB-INF/src/dao/UserDAO.java
index 4ff0869ea2e54d23cc47c48dbed8af925000eba2..20bee1fc294dfbec8568b86265d434bfcae50aec 100644
--- a/WEB-INF/src/dao/UserDAO.java
+++ b/WEB-INF/src/dao/UserDAO.java
@@ -118,6 +118,13 @@ public class UserDAO {
         return user;
     }
 
+    public boolean userExists(String login, String password) {
+        if (getUserByLogs(login, password) == null) {
+            return false;
+        } 
+        return true;
+    }
+
     public void addUser(User nUser){
         try{
             PreparedStatement stmt = this.con.prepareStatement("INSERT INTO userAccount (username, password) VALUES (?,?)");