diff --git a/htdocs/html.form.class.php b/htdocs/html.form.class.php
index 3f97af430f1..d3dbe36f70e 100644
--- a/htdocs/html.form.class.php
+++ b/htdocs/html.form.class.php
@@ -6,6 +6,7 @@
  * Copyright (C) 2004      Eric Seigne          <eric.seigne@ryxeo.com>
  * Copyright (C) 2005-2006 Regis Houssin        <regis.houssin@cap-networks.com>
  * Copyright (C) 2006      Andre Cianfarani     <acianfa@free.fr>
+ * Copyright (C) 2006      Marc Barilley/Océbo  <marc@ocebo.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -2016,7 +2017,9 @@ class Form
 					print '</script>';
 				}
 				print '<script language="javascript" type="text/javascript" src="'.DOL_URL_ROOT.'/lib/lib_calendar.js"></script>';
-				print '<input id="'.$prefix.'" type="text" name="'.$prefix.'" size="10" value="'.$formated_date.'"> ';
+				print '<input id="'.$prefix.'" type="text" name="'.$prefix.'" size="10" value="'.$formated_date.'"';
+				print ' onChange="dpChangeDay(\''.$prefix.'\',\''.$conf->format_date_short_java.'\')"';
+	            print '> ';
 				print '<input type="hidden" id="'.$prefix.'day"   name="'.$prefix.'day"   value="'.$sday.'">'."\n";
 	            print '<input type="hidden" id="'.$prefix.'month" name="'.$prefix.'month" value="'.$smonth.'">'."\n";
 	            print '<input type="hidden" id="'.$prefix.'year"  name="'.$prefix.'year"  value="'.$syear.'">'."\n";