- <option value="<?php echo $this->url("admin/users", $users_params); ?>"<?php echo $_GET[$this->param("role")] == $role["id"] ? " selected=\"selected\"" : ""; ?>><?php echo $role["intitule"]; ?></option>
+ <option value="<?php echo $this->url("admin/users", $users_params); ?>"<?php echo (isset($_GET[$this->param("role")]) && ($_GET[$this->param("role")] == $role["id"])) ? " selected=\"selected\"" : ""; ?>><?php echo $role["intitule"]; ?></option>