diff --git a/html/ajax_misc.php b/html/ajax_misc.php
index 499137641..941a41d3e 100644
--- a/html/ajax_misc.php
+++ b/html/ajax_misc.php
@@ -338,6 +338,27 @@ jr_comment,j_montant, j_debit,jr_internal from jrnx join jrn on (j_grpt=jr_grpt_
     if ( isset($_REQUEST['sc']))       $form.=HtmlInput::hidden('sc',$_REQUEST['sc']);
     if ( isset($_REQUEST['sb']))       $form.=HtmlInput::hidden('sb',$_REQUEST['sb']);
     if ( isset($_REQUEST['f_id']))       $form.=HtmlInput::hidden('f_id',$_REQUEST['f_id']);
+    /*  check if date are valid */
+    if ( (isset($search_end) && isDate($search_end) == null) ||
+	 (isset($search_start) && isDate ($search_start) == null))
+      {
+      ob_start();
+      alert(_('Date malformée, désolé'));
+      $html=ob_get_contents();
+      ob_clean();
+
+    $html=escape_xml($html);
+
+    header('Content-type: text/xml; charset=UTF-8');
+echo <<<EOF
+<?xml version="1.0" encoding="UTF-8"?>
+<data>
+<code>detail</code>
+<value>$html</value>
+</data>
+EOF;
+exit();
+    }
 
     // display a list of operation from the other side + box button
     if ( $ot == 'account') {
diff --git a/include/lettering.account.inc.php b/include/lettering.account.inc.php
index 1eeb7507e..186e0cc50 100644
--- a/include/lettering.account.inc.php
+++ b/include/lettering.account.inc.php
@@ -104,6 +104,10 @@ if ( isset($_POST['record'])) {
 // Show the result
 //--------------------------------------------------------------------------------
 echo '<div id="list">';
+if ( isDate($_GET['start']) == null || isDate($_GET['end']) == null ) {
+  echo alert(_('Date malformée, désolé'));
+  exit();
+}
 $letter=new Lettering_Account($cn);
 $letter->set_parameter('account',$_GET['acc']);
 $letter->set_parameter('start',$_GET['start']);
diff --git a/include/lettering.card.inc.php b/include/lettering.card.inc.php
index 356ed6b89..32c15c8b8 100644
--- a/include/lettering.card.inc.php
+++ b/include/lettering.card.inc.php
@@ -112,6 +112,11 @@ if ( isset($_POST['record'])) {
 // Show the result
 //--------------------------------------------------------------------------------
 echo '<div id="list">';
+if ( isDate($_GET['start']) == null || isDate($_GET['end']) == null ) {
+  echo alert(_('Date malformée, désolé'));
+  exit();
+}
+
 $letter=new Lettering_Card($cn);
 $quick_code=strtoupper(trim($_GET['acc']));
 $letter->set_parameter('quick_code',$quick_code);
diff --git a/include/lettering.gestion.inc.php b/include/lettering.gestion.inc.php
index 173b3465d..2367036b6 100644
--- a/include/lettering.gestion.inc.php
+++ b/include/lettering.gestion.inc.php
@@ -59,6 +59,11 @@ if ( isset($_POST['record'])) {
 //--------------------------------------------------------------------------------
 // Show the result
 //--------------------------------------------------------------------------------
+if ( isDate($_GET['start']) == null || isDate($_GET['end']) == null ) {
+  echo alert(_('Date malformée, désolé'));
+  exit();
+}
+
 echo '<div id="list">';
 $fiche=new Fiche($cn,$_REQUEST['f_id']);
 $quick_code=$fiche->get_quick_code();