diff --git a/htdocs/comm/action/card.php b/htdocs/comm/action/card.php
index eb2eddb3197..3c9bee038ff 100644
--- a/htdocs/comm/action/card.php
+++ b/htdocs/comm/action/card.php
@@ -55,7 +55,7 @@ $langs->load("agenda");
 $action=GETPOST('action','alpha');
 $cancel=GETPOST('cancel','alpha');
 $backtopage=GETPOST('backtopage','alpha');
-$contactid=GETPOST('contactid','int');
+$TContactId=GETPOST('TContactId','array');
 $origin=GETPOST('origin','alpha');
 $originid=GETPOST('originid','int');
 $confirm = GETPOST('confirm', 'alpha');
@@ -188,9 +188,9 @@ if ($action == 'add')
         else $backtopage=DOL_URL_ROOT.'/comm/action/index.php';
     }
 
-    if ($contactid)
+    if (!empty($TContactId[0]))
 	{
-		$result=$contact->fetch($contactid);
+		$result=$contact->fetch($TContactId[0]);
 	}
 
 	if ($cancel)
@@ -319,6 +319,9 @@ if ($action == 'add')
 		setEventMessages($langs->trans("ErrorFieldRequired", $langs->transnoentitiesnoconv("Date")), null, 'errors');
 	}
 
+	$object->TContactId = $TContactId;
+	if (!empty($object->TContactId[0])) $object->contactid = $object->TContactId[0];
+	
 	// Fill array 'array_options' with data from add form
 	$ret = $extrafields->setOptionalsFromPost($extralabels,$object);
 	if ($ret < 0) $error++;
@@ -409,7 +412,8 @@ if ($action == 'update')
         $object->fulldayevent= GETPOST("fullday")?1:0;
 		$object->location    = GETPOST('location');
 		$object->socid       = GETPOST("socid");
-		$object->contactid   = GETPOST("contactid",'int');
+		$object->TContactId   = GETPOST("TContactId",'array');
+		$object->contactid   = !empty($object->TContactId[0]) ? $object->TContactId[0] : 0;
 		//$object->societe->id = $_POST["socid"];			// deprecated
 		//$object->contact->id = $_POST["contactid"];		// deprecated
 		$object->fk_project  = GETPOST("projectid",'int');
@@ -594,9 +598,10 @@ if ($action == 'create')
 {
 	$contact = new Contact($db);
 
-	if (GETPOST("contactid"))
+	$TContactId = GETPOST("TContactId", 'array');
+	if (!empty($TContactId[0]))
 	{
-		$result=$contact->fetch(GETPOST("contactid"));
+		$result=$contact->fetch($TContactId[0]);
 		if ($result < 0) dol_print_error($db,$contact->error);
 	}
 
@@ -781,7 +786,7 @@ if ($action == 'create')
 
 	// Related contact
 	print '<tr><td class="nowrap">'.$langs->trans("ActionOnContact").'</td><td>';
-	$form->select_contacts(GETPOST('socid','int'), GETPOST('contactid'), 'contactid', 1, '', '', 0, 'minwidth200');
+	$form->select_contacts(GETPOST('socid','int'), GETPOST('TContactId', 'array'), 'TContactId[]', 1, '', '', 0, 'minwidth200',0, 0, array(), false, 'multiple', 'contactid');
 	print '</td></tr>';
 
 
@@ -880,7 +885,8 @@ if ($id > 0)
         $object->fulldayevent= GETPOST("fullday")?1:0;
 		$object->location    = GETPOST('location');
 		$object->socid       = GETPOST("socid");
-		$object->contactid   = GETPOST("contactid",'int');
+		$object->TContactId = GETPOST("TContactId",'array');
+		$object->contactid   = !empty($object->TContactId[0]) ? $object->TContactId[0] : 0;
 		//$object->societe->id = $_POST["socid"];			// deprecated
 		//$object->contact->id = $_POST["contactid"];		// deprecated
 		$object->fk_project  = GETPOST("projectid",'int');
@@ -1121,7 +1127,7 @@ if ($id > 0)
 			// related contact
 			print '<tr><td>'.$langs->trans("ActionOnContact").'</td><td>';
 			print '<div class="maxwidth200onsmartphone">';
-			$form->select_contacts($object->socid, $object->contactid, 'contactid', 1, '', '', 0, 'minwidth200');
+			$form->select_contacts($object->socid, $object->TContactId, 'TContactId[]', 1, '', '', 0, 'minwidth200',0, 0, array(), false, 'multiple', 'contactid');
 			print '</div>';
 			print '</td>';
 			print '</tr>';
@@ -1368,14 +1374,24 @@ if ($id > 0)
 			// Related contact
 			print '<tr><td>'.$langs->trans("ActionOnContact").'</td>';
 			print '<td colspan="3">';
-			if ($object->contactid > 0)
+			
+			if (!empty($object->TContactId))
 			{
-				print $object->contact->getNomUrl(1);
-				if ($object->contactid && $object->type_code == 'AC_TEL')
+				foreach ($object->TContactId as $cid)
 				{
-					if ($object->contact->fetch($object->contactid))
+					$contact = new Contact($db);
+					$result = $contact->fetch($cid);
+					
+					if ($result < 0) dol_print_error($db,$contact->error);
+					
+					if ($result > 0)
 					{
-						print "<br>".dol_print_phone($object->contact->phone_pro);
+						print $contact->getNomUrl(1).'&nbsp;';
+						if ($object->type_code == 'AC_TEL')
+						{
+							if (!empty($contact->phone_pro)) print '('.dol_print_phone($contact->phone_pro).')';
+							print '<br />';
+						}
 					}
 				}
 			}
diff --git a/htdocs/comm/action/class/actioncomm.class.php b/htdocs/comm/action/class/actioncomm.class.php
index 8243268574c..4250fc3fa6b 100644
--- a/htdocs/comm/action/class/actioncomm.class.php
+++ b/htdocs/comm/action/class/actioncomm.class.php
@@ -113,6 +113,8 @@ class ActionComm extends CommonObject
     var $userownerid;	// Id of user owner = fk_user_action into table
     var $userdoneid;	// Id of user done (deprecated)
 
+	var $socpeopleassigned = array(); // Array of user ids
+	var $TContactId = array(); // Array of user ids
     /**
      * Object user of owner
      * @var User
@@ -345,6 +347,26 @@ class ActionComm extends CommonObject
 				}
 			}
 
+			if (!$error)
+			{
+				if (!empty($this->TContactId))
+				{
+					foreach ($this->TContactId as $id)
+					{
+						$sql ="INSERT INTO ".MAIN_DB_PREFIX."actioncomm_resources(fk_actioncomm, element_type, fk_element, mandatory, transparency, answer_status)";
+						$sql.=" VALUES(".$this->id.", 'socpeople', ".$id.", 0, 0, 0)";
+						
+						$resql = $this->db->query($sql);
+						if (! $resql)
+						{
+							$error++;
+							$this->errors[]=$this->db->lasterror();
+						}
+						
+					}
+				}
+			}
+			
             if (! $error)
             {
             	$action='create';
@@ -432,7 +454,8 @@ class ActionComm extends CommonObject
 		$objFrom = clone $this;
 
 		$this->fetch_optionals();
-		$this->fetch_userassigned();
+//		$this->fetch_userassigned();
+		$this->fetchResources();
 
         $this->id=0;
 
@@ -587,6 +610,8 @@ class ActionComm extends CommonObject
 
                 $this->fk_element			= $obj->fk_element;
                 $this->elementtype			= $obj->elementtype;
+				
+                $this->fetchResources();
             }
             $this->db->free($resql);
         }
@@ -600,6 +625,51 @@ class ActionComm extends CommonObject
 
     }
 
+	/**
+     *    Initialize $this->userassigned & this->socpeopleassigned array with list of id of user and contact assigned to event
+     *
+     *    @return	int				<0 if KO, >0 if OK
+     */
+	function fetchResources()
+	{
+		$sql ='SELECT fk_actioncomm, element_type, fk_element, answer_status, mandatory, transparency';
+		$sql.=' FROM '.MAIN_DB_PREFIX.'actioncomm_resources';
+		$sql.=' WHERE fk_actioncomm = '.$this->id;
+		$resql=$this->db->query($sql);
+		if ($resql)
+		{
+			$this->userassigned=array();
+			$this->socpeopleassigned=array();
+			$this->TContactId=array();
+
+			// If owner is known, we must but id first into list
+			if ($this->userownerid > 0) $this->userassigned[$this->userownerid]=array('id'=>$this->userownerid);	// Set first so will be first into list.
+
+            while ($obj = $this->db->fetch_object($resql))
+            {
+            	if ($obj->fk_element > 0)
+				{
+					switch ($obj->element_type) {
+						case 'user':
+							$this->userassigned[$obj->fk_element]=array('id'=>$obj->fk_element, 'mandatory'=>$obj->mandatory, 'answer_status'=>$obj->answer_status, 'transparency'=>$obj->transparency);
+							if (empty($this->userownerid)) $this->userownerid=$obj->fk_element;	// If not defined (should not happened, we fix this)
+							break;
+						case 'socpeople':
+							$this->TContactId[] = $obj->fk_element;
+							$this->socpeopleassigned[$obj->fk_element]=array('id'=>$obj->fk_element, 'mandatory'=>$obj->mandatory, 'answer_status'=>$obj->answer_status, 'transparency'=>$obj->transparency);
+							break;
+					}
+				}
+            }
+
+        	return 1;
+		}
+		else
+		{
+			dol_print_error($this->db);
+			return -1;
+		}
+	}
 
     /**
      *    Initialize this->userassigned array with list of id of user assigned to event
@@ -821,6 +891,29 @@ class ActionComm extends CommonObject
 					//var_dump($sql);exit;
 				}
 			}
+			
+			if (!$error)
+			{
+				$sql ="DELETE FROM ".MAIN_DB_PREFIX."actioncomm_resources where fk_actioncomm = ".$this->id." AND element_type = 'socpeople'";
+				$resql = $this->db->query($sql);
+				
+				if (!empty($this->TContactId))
+				{
+					foreach ($this->TContactId as $id)
+					{
+						$sql ="INSERT INTO ".MAIN_DB_PREFIX."actioncomm_resources(fk_actioncomm, element_type, fk_element, mandatory, transparency, answer_status)";
+						$sql.=" VALUES(".$this->id.", 'socpeople', ".$id.", 0, 0, 0)";
+						
+						$resql = $this->db->query($sql);
+						if (! $resql)
+						{
+							$error++;
+							$this->errors[]=$this->db->lasterror();
+						}
+						
+					}
+				}
+			}
 
             if (! $error && ! $notrigger)
             {
diff --git a/htdocs/core/class/html.form.class.php b/htdocs/core/class/html.form.class.php
index 7b112a2d333..1646e660c9f 100644
--- a/htdocs/core/class/html.form.class.php
+++ b/htdocs/core/class/html.form.class.php
@@ -1253,11 +1253,13 @@ class Form
      * 	@param	int		$forcecombo		Force to use combo box
      *  @param	array	$events			Event options. Example: array(array('method'=>'getContacts', 'url'=>dol_buildpath('/core/ajax/contacts.php',1), 'htmlname'=>'contactid', 'params'=>array('add-customer-contact'=>'disabled')))
      *  @param	bool	$options_only	Return options only (for ajax treatment)
+     *  @param	string	$moreparam		Add more parameters onto the select tag. For example 'style="width: 95%"' to avoid select2 component to go over parent container	      
+     *  @param	string	$htmlid			Html id to use instead of htmlname
      *	@return	int						<0 if KO, Nb of contact in list if OK
      */
-    function select_contacts($socid,$selected='',$htmlname='contactid',$showempty=0,$exclude='',$limitto='',$showfunction=0, $moreclass='', $showsoc=0, $forcecombo=0, $events=array(), $options_only=false)
+    function select_contacts($socid,$selected='',$htmlname='contactid',$showempty=0,$exclude='',$limitto='',$showfunction=0, $moreclass='', $showsoc=0, $forcecombo=0, $events=array(), $options_only=false, $moreparam='', $htmlid='')
     {
-    	print $this->selectcontacts($socid,$selected,$htmlname,$showempty,$exclude,$limitto,$showfunction, $moreclass, $options_only, $showsoc, $forcecombo, $events);
+    	print $this->selectcontacts($socid,$selected,$htmlname,$showempty,$exclude,$limitto,$showfunction, $moreclass, $options_only, $showsoc, $forcecombo, $events, $moreparam, $htmlid);
     	return $this->num;
     }
 
@@ -1276,14 +1278,17 @@ class Form
      *	@param	integer	$showsoc	    Add company into label
      * 	@param	int		$forcecombo		Force to use combo box
      *  @param	array	$events			Event options. Example: array(array('method'=>'getContacts', 'url'=>dol_buildpath('/core/ajax/contacts.php',1), 'htmlname'=>'contactid', 'params'=>array('add-customer-contact'=>'disabled')))
+	 *  @param	string	$moreparam		Add more parameters onto the select tag. For example 'style="width: 95%"' to avoid select2 component to go over parent container	      
+     *  @param	string	$htmlid			Html id to use instead of htmlname
      *	@return	 int					<0 if KO, Nb of contact in list if OK
      */
-    function selectcontacts($socid,$selected='',$htmlname='contactid',$showempty=0,$exclude='',$limitto='',$showfunction=0, $moreclass='', $options_only=false, $showsoc=0, $forcecombo=0, $events=array())
+    function selectcontacts($socid,$selected='',$htmlname='contactid',$showempty=0,$exclude='',$limitto='',$showfunction=0, $moreclass='', $options_only=false, $showsoc=0, $forcecombo=0, $events=array(), $moreparam='', $htmlid='')
     {
         global $conf,$langs;
 
         $langs->load('companies');
 
+		if (empty($htmlid)) $htmlid = $htmlname;
         $out='';
 
         // On recherche les societes
@@ -1305,11 +1310,11 @@ class Form
             if ($conf->use_javascript_ajax && ! $forcecombo && ! $options_only)
             {
 				include_once DOL_DOCUMENT_ROOT . '/core/lib/ajax.lib.php';
-            	$comboenhancement = ajax_combobox($htmlname, $events, $conf->global->CONTACT_USE_SEARCH_TO_SELECT);
+            	$comboenhancement = ajax_combobox($htmlid, $events, $conf->global->CONTACT_USE_SEARCH_TO_SELECT);
             	$out.= $comboenhancement;
             }
 
-            if ($htmlname != 'none' || $options_only) $out.= '<select class="flat'.($moreclass?' '.$moreclass:'').'" id="'.$htmlname.'" name="'.$htmlname.'">';
+            if ($htmlname != 'none' || $options_only) $out.= '<select class="flat'.($moreclass?' '.$moreclass:'').'" id="'.$htmlid.'" name="'.$htmlname.'" '.(!empty($moreparam) ? $moreparam : '').'>';
             if ($showempty == 1) $out.= '<option value="0"'.($selected=='0'?' selected':'').'></option>';
             if ($showempty == 2) $out.= '<option value="0"'.($selected=='0'?' selected':'').'>'.$langs->trans("Internal").'</option>';
             $num = $this->db->num_rows($resql);
@@ -1319,6 +1324,7 @@ class Form
                 include_once DOL_DOCUMENT_ROOT.'/contact/class/contact.class.php';
                 $contactstatic=new Contact($this->db);
 
+                if (!is_array($selected)) $selected = array($selected);
                 while ($i < $num)
                 {
                     $obj = $this->db->fetch_object($resql);
@@ -1332,7 +1338,7 @@ class Form
                         $disabled=0;
                         if (is_array($exclude) && count($exclude) && in_array($obj->rowid,$exclude)) $disabled=1;
                         if (is_array($limitto) && count($limitto) && ! in_array($obj->rowid,$limitto)) $disabled=1;
-                        if ($selected && $selected == $obj->rowid)
+                        if (!empty($selected) && in_array($obj->rowid, $selected))
                         {
                             $out.= '<option value="'.$obj->rowid.'"';
                             if ($disabled) $out.= ' disabled';
@@ -1355,7 +1361,7 @@ class Form
                     }
                     else
 					{
-                        if ($selected == $obj->rowid)
+                        if (in_array($obj->rowid, $selected))
                         {
                             $out.= $contactstatic->getFullName($langs);
                             if ($showfunction && $obj->poste) $out.= ' ('.$obj->poste.')';
diff --git a/htdocs/install/upgrade2.php b/htdocs/install/upgrade2.php
index 36bbeb966d4..e2d18947310 100644
--- a/htdocs/install/upgrade2.php
+++ b/htdocs/install/upgrade2.php
@@ -438,6 +438,8 @@ if (! GETPOST('action','aZ09') || preg_match('/upgrade/i',GETPOST('action','aZ09
         $beforeversionarray=explode('.','6.0.9');
         if (versioncompare($versiontoarray,$afterversionarray) >= 0 && versioncompare($versiontoarray,$beforeversionarray) <= 0)
         {
+			migrate_event_assignement_contact($db,$langs,$conf);
+			
             // Reload modules (this must be always and only into last targeted version)
             $listofmodule=array(
                 'MAIN_MODULE_USER'=>'newboxdefonly',
@@ -3813,6 +3815,83 @@ function migrate_event_assignement($db,$langs,$conf)
 	print '</td></tr>';
 }
 
+/**
+ * Migrate event assignement to owner
+ *
+ * @param	DoliDB		$db				Database handler
+ * @param	Translate	$langs			Object langs
+ * @param	Conf		$conf			Object conf
+ * @return	void
+ */
+function migrate_event_assignement_contact($db,$langs,$conf)
+{
+	print '<tr><td colspan="4">';
+
+	print '<br>';
+	print '<b>'.$langs->trans('MigrationEventsContact')."</b><br>\n";
+
+	$error = 0;
+
+	dolibarr_install_syslog("upgrade2::migrate_event_assignement");
+
+	$db->begin();
+
+	$sqlSelect = "SELECT a.id, a.fk_contact";
+	$sqlSelect.= " FROM ".MAIN_DB_PREFIX."actioncomm as a";
+	$sqlSelect.= " LEFT JOIN ".MAIN_DB_PREFIX."actioncomm_resources as ar ON ar.fk_actioncomm = a.id AND ar.element_type = 'socpeople' AND ar.fk_element = a.fk_contact";
+	$sqlSelect.= " WHERE fk_contact > 0 AND fk_contact NOT IN (SELECT fk_element FROM ".MAIN_DB_PREFIX."actioncomm_resources as ar WHERE ar.fk_actioncomm = a.id AND ar.element_type = 'socpeople')";
+	$sqlSelect.= " ORDER BY a.id";
+	//print $sqlSelect;
+
+	$resql = $db->query($sqlSelect);
+	if ($resql)
+	{
+		$i = 0;
+		$num = $db->num_rows($resql);
+
+		if ($num)
+		{
+			while ($i < $num)
+			{
+				$obj = $db->fetch_object($resql);
+
+				$sqlUpdate = "INSERT INTO ".MAIN_DB_PREFIX."actioncomm_resources(fk_actioncomm, element_type, fk_element) ";
+				$sqlUpdate.= "VALUES(".$obj->id.", 'socpeople', ".$obj->fk_contact.")";
+
+				$result=$db->query($sqlUpdate);
+				if (! $result)
+				{
+					$error++;
+					dol_print_error($db);
+				}
+				print ". ";
+				$i++;
+			}
+		}
+		else
+		{
+			print $langs->trans('AlreadyDone')."<br>\n";
+		}
+
+		if (! $error)
+		{
+			$db->commit();
+		}
+		else
+		{
+			$db->rollback();
+		}
+	}
+	else
+	{
+		dol_print_error($db);
+		$db->rollback();
+	}
+
+
+	print '</td></tr>';
+}
+
 /**
  * Migrate to add entity value into llx_societe_remise
  *
diff --git a/htdocs/langs/en_US/install.lang b/htdocs/langs/en_US/install.lang
index 2b10dea91ec..d82619abbc8 100644
--- a/htdocs/langs/en_US/install.lang
+++ b/htdocs/langs/en_US/install.lang
@@ -191,6 +191,7 @@ MigrationActioncommElement=Update data on actions
 MigrationPaymentMode=Data migration for payment mode
 MigrationCategorieAssociation=Migration of categories
 MigrationEvents=Migration of events to add event owner into assignement table
+MigrationEventsContact=Migration of events to add event contact into assignement table
 MigrationRemiseEntity=Update entity field value of llx_societe_remise
 MigrationRemiseExceptEntity=Update entity field value of llx_societe_remise_except
 MigrationReloadModule=Reload module %s