diff --git a/golem_activity/models/golem_activity.py b/golem_activity/models/golem_activity.py
index f398fa6..069d68d 100644
--- a/golem_activity/models/golem_activity.py
+++ b/golem_activity/models/golem_activity.py
@@ -36,30 +36,6 @@ class GolemActivity(models.Model):
                                 required=True)
     animator_id = fields.Many2one('res.partner', string="Animator",
                                   domain=[('is_company', '=', False)])
-    places = fields.Integer('Places', default=0)
-    is_overbooked = fields.Boolean('Allow overbook?', default=False)
-    places_overbooked = fields.Integer('Places with overbook', default=0)
-
-    @api.onchange('is_overbooked', 'places')
-    def onchange_is_overbooked(self):
-        for a in self:
-            if a.places and a.is_overbooked:
-                if not a.places_overbooked or (a.places_overbooked < a.places):
-                    a.places_overbooked = a.places + 1
-
-    @api.constrains('places', 'places_overbooked')
-    def _check_places(self):
-        """ Check integers are signed and overbooked to be superior than
-        normal places """
-        for v in self:
-            for f in ['places', 'places_overbooked']:
-                if v[f] < 0:
-                    emsg = _('Number of places cannot be negative.')
-                    raise models.ValidationError(emsg)
-            if v.is_overbooked and (v.places_overbooked <= v.places):
-                emsg = _('Overbooked places cannot be inferior than places')
-                raise models.ValidationError(emsg)
-
     date_start = fields.Date('Start date')
     date_end = fields.Date('End date')
 
diff --git a/golem_activity/views/golem_activity_view.xml b/golem_activity/views/golem_activity_view.xml
index 07d9cd8..1d24974 100644
--- a/golem_activity/views/golem_activity_view.xml
+++ b/golem_activity/views/golem_activity_view.xml
@@ -42,14 +42,10 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
               <group colspan="2">
                 <field name="default_code" />
                 <field name="categ_id" />
-                <field name="animator_id" />
                 <field name="list_price" />
               </group>
               <group colspan="2">
-                <field name="places" />
-                <field name="is_overbooked" />
-                <field name="places_overbooked"
-                  attrs="{'invisible': [('is_overbooked', '=', False)]}" />
+                <field name="animator_id" />
                 <field name="date_start" />
                 <field name="date_end" />
               </group>
diff --git a/golem_activity_session/__openerp__.py b/golem_activity_session/__openerp__.py
index cf04583..9b01689 100644
--- a/golem_activity_session/__openerp__.py
+++ b/golem_activity_session/__openerp__.py
@@ -26,5 +26,5 @@
     'application': False,
     'installable': True,
     'depends': ['golem_activity'],
-    'data': ['views/golem_activity_view.xml']
+    'data': ['views/golem_activity_view.xml', 'views/golem_member_view.xml']
 }
diff --git a/golem_activity_session/models/golem_activity_session.py b/golem_activity_session/models/golem_activity_session.py
index 46c71fa..011fbbb 100644
--- a/golem_activity_session/models/golem_activity_session.py
+++ b/golem_activity_session/models/golem_activity_session.py
@@ -18,6 +18,13 @@
 from openerp import models, fields, api, _
 
 
+class GolemMember(models.Model):
+    _inherit = 'golem.member'
+
+    activity_session_ids = fields.Many2many('golem.activity.session',
+                                            string='Activities')
+
+
 class GolemActivity(models.Model):
     _inherit = 'golem.activity'
 
@@ -53,12 +60,12 @@ class GolemActivitySession(models.Model):
         for s in self:
             s.name = s.activity_id.activity_name
 
-    # TODO: reucrrence etc... to link with calendar.event
+    member_ids = fields.Many2many('golem.member', string='Members')
+    # TODO: recurrence etc... to link with calendar.event
     activity_id = fields.Many2one('golem.activity', string='Activité',
                                   required=True)
-    animator_id = fields.Many2one('res.partner', string='Animator',
-                                  required=True)
-    is_recurrent = fields.Boolean('Is recurrent ?', default=False,
+    animator_id = fields.Many2one('res.partner', string='Animator')
+    is_recurrent = fields.Boolean('Is recurrent ?', default=True,
                                   help="Work in progress")
     weekday = fields.Selection([('mon', _('Monday')),
                                 ('tue', _('Tuesday')),
@@ -69,7 +76,6 @@ class GolemActivitySession(models.Model):
                                 ('sun', _('Sunday'))])
     hour_start = fields.Float('Start time')
     hour_end = fields.Float('End time')
-    note = fields.Text('Note')
 
     @api.constrains('hour_start', 'hour_end')
     def _check_period(self):
@@ -78,3 +84,48 @@ class GolemActivitySession(models.Model):
             if s.hour_start > s.hour_end:
                 raise models.ValidationError(_('Start of the period cannot be '
                                                'after end of the period.'))
+
+    places = fields.Integer('Places', default=0)
+    is_overbooked = fields.Boolean('Allow overbook?', default=False)
+    places_overbooked = fields.Integer('Places with overbook', default=0)
+    places_remain = fields.Integer('Remaining places', store=True,
+                                   compute='_compute_places_remain')
+
+    @api.depends('places', 'is_overbooked', 'places_overbooked', 'member_ids')
+    def _compute_places_remain(self):
+        for s in self:
+            used = len(s.member_ids)
+            if not s.is_overbooked:
+                s.places_remain = s.places - used
+            else:
+                s.places_remain = s.places_overbooked - used
+
+    @api.constrains('places_remain')
+    def _check_remaining_places(self):
+        """ Forbid inscription when there is no more place """
+        for s in self:
+            if s.places_remain < 0:
+                emsg = _('Sorry, there is no more place !')
+                raise models.ValidationError(emsg)
+
+    @api.onchange('is_overbooked', 'places')
+    def onchange_is_overbooked(self):
+        for s in self:
+            if s.places and s.is_overbooked:
+                if not s.places_overbooked or (s.places_overbooked < s.places):
+                    s.places_overbooked = s.places + 1
+
+    @api.constrains('places', 'places_overbooked')
+    def _check_places(self):
+        """ Check integers are signed and overbooked to be superior than
+        normal places """
+        for v in self:
+            for f in ['places', 'places_overbooked']:
+                if v[f] < 0:
+                    emsg = _('Number of places cannot be negative.')
+                    raise models.ValidationError(emsg)
+            if v.is_overbooked and (v.places_overbooked <= v.places):
+                emsg = _('Overbooked places cannot be inferior than places')
+                raise models.ValidationError(emsg)
+
+    note = fields.Text('Note')
diff --git a/golem_activity_session/views/golem_activity_view.xml b/golem_activity_session/views/golem_activity_view.xml
index fa35a06..0b28634 100644
--- a/golem_activity_session/views/golem_activity_view.xml
+++ b/golem_activity_session/views/golem_activity_view.xml
@@ -43,6 +43,10 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
               <group>
                 <field name="activity_id" />
                 <field name="animator_id" />
+                <field name="places" />
+                <field name="is_overbooked" />
+                <field name="places_overbooked"
+                  attrs="{'invisible': [('is_overbooked', '=', False)]}" />
               </group>
               <group>
                 <field name="is_recurrent" readonly="True" />
@@ -51,16 +55,24 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
                 <field name="hour_end" widget="float_time" />
               </group>
             </group>
-            <group>
-              <field name="note" />
-            </group>
+            <notebook>
+              <page string="Members">
+                <group>
+                  <field name="places_remain" readonly="True" />
+                  <field name="member_ids" />
+                </group>
+              </page>
+              <page string="Note">
+                <field name="note" />
+              </page>
+            </notebook>
           </sheet>
         </form>
       </field>
     </record>
 
     <!-- Tree -->
-    <record id="family_tree" model="ir.ui.view">
+    <record id="session_tree" model="ir.ui.view">
       <field name="name">Session list</field>
       <field name="model">golem.activity.session</field>
       <field name="arch" type="xml">
diff --git a/golem_activity_session/views/golem_member_view.xml b/golem_activity_session/views/golem_member_view.xml
new file mode 100644
index 0000000..3d882fc
--- /dev/null
+++ b/golem_activity_session/views/golem_member_view.xml
@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+Copyright 2016 Fabien Bourgeois <fabien@yaltik.com>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+-->
+<openerp>
+  <data>
+
+    <!-- Form -->
+    <record model="ir.ui.view" id="sessions_inscription">
+      <field name="name">Add sessions inscriptions to member form</field>
+      <field name="model">golem.member</field>
+      <field name="inherit_id" ref="golem_member.view_form" />
+      <field name="arch" type="xml">
+        <page name="other_page" position="after">
+          <page name="sessions" string="Activities">
+            <field name="activity_session_ids" />
+          </page>
+        </page>
+      </field>
+    </record>
+
+  </data>
+</openerp>