diff --git a/include/ac_common.php b/include/ac_common.php
new file mode 100644
index 000000000..af0cd89a9
--- /dev/null
+++ b/include/ac_common.php
@@ -0,0 +1,145 @@
+ 0 date1 > date2
+ * - < 0 date1 < date2
+ */
+
+function cmpDate ($p_date,$p_date_oth) {
+ $l_date=isDate($p_date);
+ $l2_date=isDate($p_date_oth);
+ if ($l_date == null || $l2_date == null ) {
+ echo "erreur date";
+ return null;
+ }
+ $l_adate=explode(".",$l_date);
+ $l2_adate=explode(".",$l2_date);
+ $l_mkdate=mktime(0,0,0,$l_adate[1],$l_adate[0],$l_adate[2]);
+ $l2_mkdate=mktime(0,0,0,$l2_adate[1],$l2_adate[0],$l2_adate[2]);
+ // si $p_date > $p_date_oth return > 0
+ return $l_mkdate-$l2_mkdate;
+}
+/* function isDate
+ * Purpose : Verifie qu'une date est bien formaté
+ * en d.m.y et est valable
+ * parm :
+ * - $p_date
+ * gen :
+ * - rien
+ * return:
+ * - null si la date est invalide ou malformaté
+ * - $p_date si tout est bon
+ *
+ */
+
+function isDate ( $p_date) {
+ if ( strlen (trim($p_date)) == 0 ) return null;
+ if (! ereg ("^[0-9]{1,2}\.[0-9]{1,2}\.20[0-9]{2}",$p_date) ) {
+
+ return null;
+ } else {
+ $l_date=explode(".",$p_date);
+ if ( $l_date[2] > 2020 ) {
+ return null;
+ }
+ if ( checkdate ($l_date[1],$l_date[0],$l_date[2]) == false) {
+ return null;
+ }
+
+ }// !ereg
+ return $p_date;
+}
+function formatDate($p_date) {
+ if ( isDate($p_date)== null) return "null";
+ return "'".$p_date."'";
+}
+function html_page_start($p_first=0,$p_script="")
+{
+ global $user,$pass,$IsValid;
+ if ($p_first == 1 ) {
+ echo_debug("Start session explicit");
+ session_start();
+ }
+ session_register("user");
+ session_register("pass");
+ session_register("IsValid");
+
+ echo_debug("user = ".$user." pass=".$pass." IsValid = $IsValid");
+ echo '';
+ echo "";
+ echo "
+ Gnu Accountancy
+
+ ";
+ echo "";
+}
+function html_page_stop()
+{
+ echo "";
+ echo "";
+}
+function html_button_logout() {
+ echo " Logout ";
+}
+function NoAccess() {
+ // echo '';
+ echo "
";
+ echo "