diff --git a/htdocs/comm/action/card.php b/htdocs/comm/action/card.php
index aefc94e85f4..9d17127aebe 100644
--- a/htdocs/comm/action/card.php
+++ b/htdocs/comm/action/card.php
@@ -652,8 +652,7 @@ if (empty($reshook) && $action == 'confirm_delete' && GETPOST("confirm") == 'yes
  */
 if (empty($reshook) && GETPOST('actionmove', 'alpha') == 'mupdate')
 {
-    //$object->fetch($id);
-    //$object->fetch_userassigned();
+    $error = 0;
 
     $shour = dol_print_date($object->datep, "%H");
     $smin = dol_print_date($object->datep, "%M");
@@ -673,10 +672,76 @@ if (empty($reshook) && GETPOST('actionmove', 'alpha') == 'mupdate')
             $object->datef+=$datep-$object->datep;
         }
         $object->datep=$datep;
-        $result=$object->update($user);
-        if ($result < 0)
-        {
-            setEventMessages($object->error, $object->errors, 'errors');
+
+        if (!$error) {
+            // check if an event resource is already in use
+            if (!empty($conf->global->RESOURCE_USED_IN_EVENT_CHECK) && $object->element == 'action') {
+                $eventDateStart = $object->datep;
+                $eventDateEnd = $object->datef;
+
+                $sql  = "SELECT er.rowid, r.ref as r_ref, ac.id as ac_id, ac.label as ac_label";
+                $sql .= " FROM " . MAIN_DB_PREFIX . "element_resources as er";
+                $sql .= " INNER JOIN " . MAIN_DB_PREFIX . "resource as r ON r.rowid = er.resource_id AND er.resource_type = 'dolresource'";
+                $sql .= " INNER JOIN " . MAIN_DB_PREFIX . "actioncomm as ac ON ac.id = er.element_id AND er.element_type = '" . $db->escape($object->element) . "'";
+                $sql .= " WHERE ac.id != " . $object->id;
+                $sql .= " AND er.resource_id IN (";
+                $sql .= " SELECT resource_id FROM " . MAIN_DB_PREFIX . "element_resources";
+                $sql .= " WHERE element_id = " . $object->id;
+                $sql .= " AND element_type = '" . $db->escape($object->element) . "'";
+                $sql .= " AND busy = 1";
+                $sql .= ")";
+                $sql .= " AND er.busy = 1";
+                $sql .= " AND (";
+
+                // event date start between ac.datep and ac.datep2 (if datep2 is null we consider there is no end)
+                $sql .= " (ac.datep <= '" . $db->idate($eventDateStart) . "' AND (ac.datep2 IS NULL OR ac.datep2 >= '" . $db->idate($eventDateStart) . "'))";
+                // event date end between ac.datep and ac.datep2
+                if (!empty($eventDateEnd)) {
+                    $sql .= " OR (ac.datep <= '" . $db->idate($eventDateEnd) . "' AND (ac.datep2 >= '" . $db->idate($eventDateEnd) . "'))";
+                }
+                // event date start before ac.datep and event date end after ac.datep2
+                $sql .= " OR (";
+                $sql .= "ac.datep >= '" . $db->idate($eventDateStart) . "'";
+                if (!empty($eventDateEnd)) {
+                    $sql .= " AND (ac.datep2 IS NOT NULL AND ac.datep2 <= '" . $db->idate($eventDateEnd) . "')";
+                }
+                $sql .= ")";
+
+                $sql .= ")";
+                $resql = $db->query($sql);
+                if (!$resql) {
+                    $error++;
+                    $object->error = $db->lasterror();
+                    $object->errors[] = $object->error;
+                } else {
+                    if ($db->num_rows($resql) > 0) {
+                        // already in use
+                        $error++;
+                        $object->error = $langs->trans('ErrorResourcesAlreadyInUse') . ' : ';
+                        while ($obj = $db->fetch_object($resql)) {
+                            $object->error .= '<br> - ' . $langs->trans('ErrorResourceUseInEvent', $obj->r_ref, $obj->ac_label . ' [' . $obj->ac_id . ']');
+                        }
+                        $object->errors[] = $object->error;
+                    }
+                    $db->free($resql);
+                }
+
+                if ($error) {
+                    setEventMessages($object->error, $object->errors, 'errors');
+                }
+            }
+        }
+
+        if (!$error) {
+            $db->begin();
+            $result = $object->update($user);
+            if ($result < 0) {
+                $error++;
+                setEventMessages($object->error, $object->errors, 'errors');
+                $db->rollback();
+            } else {
+                $db->commit();
+            }
         }
     }
     if (! empty($backtopage))