diff --git a/debian/alternc.config b/debian/alternc.config
index edd58040..df7a824c 100644
--- a/debian/alternc.config
+++ b/debian/alternc.config
@@ -63,6 +63,24 @@ check_mysql(){
 
 }
 
+function get_first_existing_dir() {
+  # Prend en premier parametre un chemin
+  # Retourne le répertoire parent existant le plus "proche"
+  # Exemple: on lui donne /var/www/alternc/gerard/dupont/ mais
+  # seul /var/www/alternc existe, ca répond /var/www/alternc
+  dir="$1"
+  if [ -z "$dir" ] ; then
+    return 0
+  fi
+  if ! test -d "$dir" ; then
+    get_first_existing_dir "$(dirname "$dir")"
+  else
+    echo "$dir"
+  fi
+}
+
+
+
 # default values for local.sh
 MYSQL_HOST=127.0.0.1
 MYSQL_DATABASE=alternc
@@ -192,10 +210,12 @@ while [ "$QUEST_STATE" != 0 -a "$QUEST_STATE" != 13 ]; do
 
     ALTERNC_HTML="$RET"
     #checking acl and quota activation.
-    MOUNT_POINT=$(df -P ${ALTERNC_HTML%/*} | tail -n 1 | awk '{print $6}')
-    aclcheckfile="$ALTERNC_HTML/test-acl"
+    basedir=`get_first_existing_dir "$ALTERNC_HTML"`;
+    MOUNT_POINT=$(df -P ${basedir%/*} | tail -n 1 | awk '{print $6}')
+    #we get the first existing dir
+    aclcheckfile="$basedir/test-acl"
     touch "$aclcheckfile"
-    setfacl -m u:root:rwx "$aclcheckfile" 2>/dev/null || ( echo "Error : ACL aren't activated on $ALTERNC_HTML AlternC can't work without it." ; exit 2)
+    setfacl -m u:root:rwx "$aclcheckfile" 2>/dev/null || ( echo "Error : ACL aren't activated on $basedir AlternC can't work without it." ; exit 2)
 
     if [ $? -ne 0 ]; then
       db_input critical alternc/acluninstalled || true
@@ -205,7 +225,7 @@ while [ "$QUEST_STATE" != 0 -a "$QUEST_STATE" != 13 ]; do
       exit 2
     fi
 
-    quota_activation=$(quota -gA -f $MOUNT_POINT >/dev/null)
+    quota_activation=`$(quota -gA -f $MOUNT_POINT >/dev/null)`
 
     
     if [ $? -ne 0 ]; then