diff --git a/htdocs/eventorganization/class/conferenceorboothattendee.class.php b/htdocs/eventorganization/class/conferenceorboothattendee.class.php
index 3b0795ef2a0..ef5e85c7229 100644
--- a/htdocs/eventorganization/class/conferenceorboothattendee.class.php
+++ b/htdocs/eventorganization/class/conferenceorboothattendee.class.php
@@ -104,7 +104,7 @@ class ConferenceOrBoothAttendee extends CommonObject
 		'ref' => array('type'=>'varchar(128)', 'label'=>'Ref', 'enabled'=>'1', 'position'=>10, 'notnull'=>1, 'visible'=>2, 'index'=>1, 'comment'=>"Reference of object"),
 		'fk_soc' => array('type'=>'integer:Societe:societe/class/societe.class.php:1:status=1 AND entity IN (__SHARED_ENTITIES__)', 'label'=>'Attendee', 'enabled'=>'1', 'position'=>50, 'notnull'=>-1, 'visible'=>1, 'index'=>1, 'help'=>"LinkToThirparty",),
 		'fk_actioncomm' => array('type'=>'integer:ActionComm:comm/action/class/actioncomm.class.php:1', 'label'=>'ConferenceOrBooth', 'enabled'=>'1', 'position'=>53, 'notnull'=>1, 'visible'=>0, 'index'=>1,),
-		'email' => array('type'=>'mail', 'label'=>'Email', 'enabled'=>'1', 'position'=>55, 'notnull'=>0, 'visible'=>1, 'index'=>1,),
+		'email' => array('type'=>'mail', 'label'=>'Email', 'enabled'=>'1', 'position'=>55, 'notnull'=>1, 'visible'=>1, 'index'=>1,),
 		'date_subscription' => array('type'=>'datetime', 'label'=>'DateSubscription', 'enabled'=>'1', 'position'=>56, 'notnull'=>0, 'visible'=>1, 'showoncombobox'=>'1',),
 		'amount' => array('type'=>'price', 'label'=>'AmountOfSubscriptionPaid', 'enabled'=>'1', 'position'=>57, 'notnull'=>0, 'visible'=>1, 'default'=>'null', 'isameasure'=>'1', 'help'=>"AmountOfSubscriptionPaid",),
 		'note_public' => array('type'=>'html', 'label'=>'NotePublic', 'enabled'=>'1', 'position'=>61, 'notnull'=>0, 'visible'=>0,),
@@ -745,6 +745,10 @@ class ConferenceOrBoothAttendee extends CommonObject
 			if ($option == 'conforboothid') {
 				$url .= '&conforboothid='.$this->fk_actioncomm;
 			}
+
+			if ($option == 'conforboothidproject') {
+				$url .= '&conforboothid='.$this->fk_actioncomm.'&withproject=1' ;
+			}
 		}
 
 		$linkclose = '';
diff --git a/htdocs/eventorganization/conferenceorboothattendee_card.php b/htdocs/eventorganization/conferenceorboothattendee_card.php
index 57cf6baba78..68f6c4eef13 100644
--- a/htdocs/eventorganization/conferenceorboothattendee_card.php
+++ b/htdocs/eventorganization/conferenceorboothattendee_card.php
@@ -110,7 +110,12 @@ if ($reshook < 0) {
 if (empty($reshook)) {
 	$error = 0;
 
-	$backurlforlist = dol_buildpath('/eventorganization/conferenceorboothattendee_list.php', 1);
+	if (!empty($withproject)) {
+		$backurlforlist = dol_buildpath('/eventorganization/conferenceorboothattendee_list.php?withproject=1', 1);
+	} else {
+		$backurlforlist = dol_buildpath('/eventorganization/conferenceorboothattendee_list.php', 1);
+	}
+
 
 	if (empty($backtopage) || ($cancel && empty($id))) {
 		if (empty($backtopage) || ($cancel && strpos($backtopage, '__ID__'))) {
@@ -492,7 +497,7 @@ if ($object->id > 0 && (empty($action) || ($action != 'edit' && $action != 'crea
 
 	// Object card
 	// ------------------------------------------------------------
-	$linkback = '<a href="'.dol_buildpath('/eventorganization/conferenceorboothattendee_list.php', 1).'?restore_lastsearch_values=1&conforboothid='.$confOrBooth->id .'">'.$langs->trans("BackToList").'</a>';
+	$linkback = '<a href="'.dol_buildpath('/eventorganization/conferenceorboothattendee_list.php', 1).'?restore_lastsearch_values=1&conforboothid='.$confOrBooth->id .$withProjectUrl.'">'.$langs->trans("BackToList").'</a>';
 
 	$morehtmlref = '<div class="refidno">';
 	/*
diff --git a/htdocs/eventorganization/conferenceorboothattendee_list.php b/htdocs/eventorganization/conferenceorboothattendee_list.php
index d62830de925..0505f6c7461 100644
--- a/htdocs/eventorganization/conferenceorboothattendee_list.php
+++ b/htdocs/eventorganization/conferenceorboothattendee_list.php
@@ -604,7 +604,7 @@ print '<input type="hidden" name="sortfield" value="'.$sortfield.'">';
 print '<input type="hidden" name="sortorder" value="'.$sortorder.'">';
 print '<input type="hidden" name="contextpage" value="'.$contextpage.'">';
 
-$newcardbutton = dolGetButtonTitle($langs->trans('New'), '', 'fa fa-plus-circle', DOL_URL_ROOT.'/eventorganization/conferenceorboothattendee_card.php?action=create'.(!empty($confOrBooth->id)?'&conforboothid='.$confOrBooth->id:'').$withProjectUrl.'&backtopage='.urlencode($_SERVER['PHP_SELF']).(!empty($confOrBooth->id)?'?conforboothid='.$confOrBooth->id:'').$withProjectUrl, '', $permissiontoadd);
+$newcardbutton = dolGetButtonTitle($langs->trans('New'), '', 'fa fa-plus-circle', DOL_URL_ROOT.'/eventorganization/conferenceorboothattendee_card.php?action=create'.(!empty($confOrBooth->id)?'&conforboothid='.$confOrBooth->id:'').$withProjectUrl.'&backtopage='.urlencode($_SERVER['PHP_SELF'].(!empty($confOrBooth->id)?'?conforboothid='.$confOrBooth->id:'').$withProjectUrl), '', $permissiontoadd);
 
 print_barre_liste($title, $page, $_SERVER["PHP_SELF"], $param, $sortfield, $sortorder, $massactionbutton, $num, $nbtotalofrecords, 'object_'.$object->picto, 0, $newcardbutton, '', $limit, 0, 0, 1);
 
@@ -776,7 +776,7 @@ while ($i < ($limit ? min($num, $limit) : $num)) {
 			if ($key == 'status') {
 				print $object->getLibStatut(5);
 			} elseif ($key == 'ref') {
-				print $object->getNomUrl(1, 'conforboothid');
+				print $object->getNomUrl(1, (!empty($withproject)?'conforboothidproject':'conforboothid'));
 			} else {
 				print $object->showOutputField($val, $key, $object->$key, '');
 			}
diff --git a/htdocs/projet/class/project.class.php b/htdocs/projet/class/project.class.php
index 7fc9646c489..11af1f4ea13 100644
--- a/htdocs/projet/class/project.class.php
+++ b/htdocs/projet/class/project.class.php
@@ -115,6 +115,17 @@ class Project extends CommonObject
 	 */
 	public $usage_bill_time; // Is the time spent on project must be invoiced or not
 
+	/**
+	 * @var boolean Use opportunities management
+	 */
+	public $usage_opportunity;
+
+	/**
+	 * @var boolean Use task management
+	 */
+	public $usage_task;
+
+
 	/**
 	 * @var boolean Event organization: Use Event Organization
 	 */