diff --git a/db_backend.php b/db_backend.php
index 182a1c7..d028241 100644
--- a/db_backend.php
+++ b/db_backend.php
@@ -34,7 +34,9 @@
                 $a[$key] = $value;
             }
         }
-        $a["participation_confirmed_at"] = date("Y-m-d H:i:s UTC");
+        if ($user->participation_confirmed) {
+            $a["participation_confirmed_at"] = date("Y-m-d H:i:s UTC");
+        }
         $keys = array_keys($a);
         $sql = "INSERT INTO person (" . implode(", ", $keys) . ") \n";
         $sql .= "VALUES ( :" . implode(", :", $keys) . ")";
@@ -55,11 +57,11 @@
             $stmt = $this->pdo->prepare($sql);
             $stmt->bindValue(':table', $table, PDO::PARAM_STR);
             $stmt->execute();
-            $output = array();
+            $persons = array();
             while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
-                $output[$row['COLUMN_NAME']] = $row['COLUMN_NAME'];
+                $persons[$row['COLUMN_NAME']] = $row['COLUMN_NAME'];
             }
-            return $output;
+            return $persons;
         } catch (PDOException $pe) {
             trigger_error('Could not connect to MySQL database. ' . $pe->getMessage(), E_USER_ERROR);
         }
@@ -78,7 +80,7 @@
 
     function mail_count($email)
     {
-        $sql = "SELECT COUNT(*) FROM person WHERE email = :email";
+        $sql = "SELECT COUNT(*) FROM person WHERE email = :email AND participation_confirmed";
         try {
             $stmt = $this->pdo->prepare($sql);
             $stmt->bindValue(':email', $email, PDO::PARAM_STR);
@@ -89,4 +91,23 @@
             trigger_error('Could not connect to MySQL database. ' . $pe->getMessage(), E_USER_ERROR);
         }
     }
+
+    function get_persons($filter)
+    {
+        $sql = "SELECT *, NULL as invoice FROM person " . ($filter?  "WHERE " . $filter : '');   
+
+        try {
+            $stmt = $this->pdo->prepare($sql);
+            $stmt->execute();
+            $persons = array();
+            while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
+                $user = new User();
+                $user->init_from_array($row);
+                $persons[] = $user;
+            }
+            return $persons;
+        } catch (PDOException $pe) {
+            trigger_error('Could not connect to MySQL database. ' . $pe->getMessage(), E_USER_ERROR);
+        }
+    }
 }