diff --git a/TODO b/TODO
index a8d3704..96cd7bd 100755
--- a/TODO
+++ b/TODO
@@ -5,11 +5,6 @@
 * User groups
 * cf TODO in files
 
-inc/Invoices.class.php :
-========================
-* Edit a bill
-* Error in guest input on token error
-
 Manage paybacks :
 =================
 * TODO : Payback system (class should be ok)
diff --git a/inc/Invoices.class.php b/inc/Invoices.class.php
index 9d801b6..3e37472 100644
--- a/inc/Invoices.class.php
+++ b/inc/Invoices.class.php
@@ -20,7 +20,6 @@
         public function __construct() {
             parent::__construct();
             $this->users_in = new UsersIn();
-            $this->date = new DateTime();
         }
 
         // Getters
@@ -30,7 +29,10 @@
         }
 
         public function getDate($format = "d-m-Y H:i") {
-            return $this->date->format($format);
+            if(!empty($this->date))
+                return $this->date->format($format);
+            else
+                return false;
         }
 
         public function getBuyer() {
@@ -90,7 +92,6 @@
             $this->what = htmlspecialchars($this->what);
             $this->amount = (float) $this->amount;
             $this->buyer = (int) $this->buyer;
-            // TODO : $this->date = htmlspecialchars($this->date);
 
             return $this;
         }
@@ -106,7 +107,8 @@
             $this->setWhat($data['what']);
             $this->setAmount($data['amount']);
             $this->setBuyer($data['buyer']);
-            //TODO : $this->setDate($data['date']);
+
+            $this->date = DateTime::createFromFormat('Y-m-d H:i:s', $data['date']);
         }
         
         // Override parent load() method
@@ -114,20 +116,31 @@
         public function load($fields = NULL, $first_only = false) {
             $return = parent::load($fields, $first_only); // Execute parent load
 
-            if($return !== false) {
+            if(is_array($return)) {
                 foreach(array_keys($return) as $key) {
                     $return[$key]->users_in->load(); // Load users in for each invoice
                 }
             }
+            elseif(is_a($return, 'Invoice')) {
+                $return->users_in->load();
+            }
 
             return $return; // Return the loaded elements
         }
 
-        // Overrid parent save() method
+        // Override parent save() method
         // ============================
         public function save() {
             parent::save(); // Save invoice element
 
             $this->users_in->save(); // Save users in
         }
+
+        // Override parent delete() method
+        // ===============================
+        public function delete() {
+            parent::delete(); // Delete invoice element
+
+            $this->users_in->delete(); // Also delete users in
+        }
     }
diff --git a/inc/Storage.class.php b/inc/Storage.class.php
index 3f57eac..c9c36fa 100644
--- a/inc/Storage.class.php
+++ b/inc/Storage.class.php
@@ -264,10 +264,12 @@ class Storage {
 
         foreach($this->fields as $field=>$type) {
             if(!empty($this->$field)) {
-                if($fields[$field] == 'date')
-                    $value = $value->format('Y-m-d H:i:s');
+                if($this->fields[$field] == 'date')
+                    $value = $this->$field->format('Y-m-d H:i:s');
+                else
+                    $value = $this->$field;
 
-                $query->bindParam(':'.$field, $this->$field);
+                $query->bindValue(':'.$field, $value);
             }
         }
 
diff --git a/inc/UsersIn.class.php b/inc/UsersIn.class.php
index 9acf21c..0a85bbf 100644
--- a/inc/UsersIn.class.php
+++ b/inc/UsersIn.class.php
@@ -114,4 +114,12 @@
                 $query->execute();
             }
         }
+
+        // Override delete() method
+        // ========================
+        public function delete() {
+            $query = $this->getConnection()->prepare('DELETE FROM '.MYSQL_PREFIX.$this->TABLE_NAME.' WHERE invoice_id=:invoice_id');
+            $query->bindParam(':invoice_id', $this->invoice_id);
+            $query->execute();
+        }
     }
diff --git a/inc/functions.php b/inc/functions.php
index b7ca44b..40258f2 100644
--- a/inc/functions.php
+++ b/inc/functions.php
@@ -81,6 +81,7 @@
     }
 
     function formatUsersIn($users_in, $all_users) {
+        global $localized;
         // TODO : Move this function to somewhere else ?
         $return = '';
         $users_in = $users_in->get();
@@ -91,10 +92,10 @@
 
             $return .= $all_users[$user_in]->getDisplayName();
             if($guests != 0) {
-                if($guest > 1)
-                    $return .= ' ('.$guests.' '.$localized['guest'].'s)';
+                if($guests > 1)
+                    $return .= ' ('.$guests.' '.$localized['guest'][LANG].'s)';
                 else 
-                    $return .= ' ('.$guests.' '.$localized['guest'].')';
+                    $return .= ' ('.$guests.' '.$localized['guest'][LANG].')';
             }
         }
 
diff --git a/index.php b/index.php
index a3ec6c7..e11d35a 100644
--- a/index.php
+++ b/index.php
@@ -8,7 +8,8 @@
         'write_error_data'=>array('fr'=>'Le script ne peut pas écrire dans le dossier data/, vérifiez les permissions sur ce dossier.', 'en'=>'The script can\'t write in data/ dir, check permissions set on this folder.'),
         'unable_write_config'=>array('fr'=>'Impossible d\'écrire le fichier data/config.php. Vérifiez les permissions.', 'en'=>'Unable to write data/config.php file. Check permissions.'),
         'negative_amount'=>array('fr'=>'Montant négatif non autorisé.', 'en'=>'Negative amount not allowed.'),
-        'template_error'=>array('fr'=>'Template non disponible.', 'en'=>'Template not available.')
+        'template_error'=>array('fr'=>'Template non disponible.', 'en'=>'Template not available.'),
+        'unauthorized'=>array('fr'=>'Vous n\'avez pas le droit de faire cette action.', 'en'=>'You are not authorized to do that.')
     );
 
     $localized = array(
@@ -448,15 +449,25 @@
             break;
 
         case 'delete_invoice':
-            // TODO : Check user has right to do it
             if(!empty($_GET['id'])) {
                 $invoice = new Invoice();
-                $invoice->setId($_GET['id']);
-                $invoice->delete();
+                $invoice = $invoice->load(array('id'=>(int) $_GET['id']), true);
 
-                // Clear the cache
-                array_map("unlink", glob(raintpl::$cache_dir."*.rtpl.php"));
+                if($current_user->getAdmin() || $invoice->getBuyer() == $current_user->getId()) {
+                    $invoice->delete();
 
+                    // Clear the cache
+                    array_map("unlink", glob(raintpl::$cache_dir."*.rtpl.php"));
+
+                    header('location: index.php?'.$get_redir);
+                    exit();
+                }
+                else {
+                    $tpl->assign('error', $errors['unauthorized']);
+                    $tpl->draw('index');
+                }
+            }
+            else {
                 header('location: index.php?'.$get_redir);
                 exit();
             }
@@ -464,10 +475,10 @@
 
         default:
             // Display cached page in priority
-            /* TODO if($cache = $tpl->cache('index', $expire_time = 600, $cache_id = $current_user->getLogin())) {
+            if($cache = $tpl->cache('index', $expire_time = 600, $cache_id = $current_user->getLogin())) {
                 echo $cache;
             }
-            else { */
+            else {
                 $users_list = new User();
                 $users_list = $users_list->load();
 
@@ -482,5 +493,5 @@
 
                 $tpl->draw('index');
                 break;
-            //}
+            }
     }
diff --git a/tpl/default_en/edit_users.html b/tpl/default_en/edit_users.html
index 3f6aae5..2f95f02 100644
--- a/tpl/default_en/edit_users.html
+++ b/tpl/default_en/edit_users.html
@@ -1,9 +1,5 @@
 {include="header"}
 
-{if condition="$error != ''"}
-    <p class="error">{$error}</p>
-{/if}
-
 {if condition="$view == 'list_users'"}
 <h2>List of users</h2>
 <p class="center">You can also <a href="?do=add_user">add a user</a>.</p>
diff --git a/tpl/default_en/header.html b/tpl/default_en/header.html
index 920c212..a02008b 100755
--- a/tpl/default_en/header.html
+++ b/tpl/default_en/header.html
@@ -27,3 +27,4 @@
     {/if}
 </div>
 {/if}
+{if condition="!empty($error)"}<p class="error">{$error}</p>{/if}
diff --git a/tpl/default_en/index.html b/tpl/default_en/index.html
index f5b45cb..c058c60 100755
--- a/tpl/default_en/index.html
+++ b/tpl/default_en/index.html
@@ -27,7 +27,7 @@
 <div id="detailed_summary">
     <h2>Detailed list of bills for last month</h2>
 
-    {if condition="count($invoices)>=1"}
+    {if condition="$invoices !== false && count($invoices)>=1"}
         <table id="list_expenses">
             <tr>
                 <th>Date</th>
@@ -40,7 +40,7 @@
             </tr>
             {loop="invoices"}
                 <tr>
-                    <td>{$value->getDate()}</td>
+                    <td>{$value->getDate('d-m-Y A')}</td>
                     <td>{$users[$value->getBuyer()]->getDisplayName()}</td>
                     <td>{function="formatUsersIn($value->getUsersIn(), $users)"}</td>
                     <td>{$value->getAmount()}</td>
diff --git a/tpl/default_en/new_invoice.html b/tpl/default_en/new_invoice.html
index 7826484..92ef083 100755
--- a/tpl/default_en/new_invoice.html
+++ b/tpl/default_en/new_invoice.html
@@ -1,9 +1,5 @@
 {include="header"}
 
-{if condition="$error != ''"}
-    <p class="error">{$error}</p>
-{/if}
-
 <h2>Add a bill</h2>
 
 <form method="post" action="index.php?do=new_invoice" id="invoice_form">
diff --git a/tpl/default_en/settings.html b/tpl/default_en/settings.html
index 32999fa..8556ffb 100644
--- a/tpl/default_en/settings.html
+++ b/tpl/default_en/settings.html
@@ -2,7 +2,6 @@
 
 {if condition="!$show_settings"}
 <h2>Edit homepage notice</h2>
-{if condition="$error"}<p class="error">{$error}</p>{/if}
 <form method="post" id="notice_form" action="index.php?do=edit_notice">
     <p>
         <label for="textarea_notice">Homepage notice :</label><br/>
@@ -17,7 +16,6 @@
 
 {else}
 <h2>Change settings of your Bouffe@Ulm installation</h2>
-{if condition="$error"}<p class="error">{$error}</p>{/if}
 <form method="post" action="index.php?do=settings" id="settings_form">
     <fieldset>
         <legend>Database</legend>