diff --git a/sub_project/models/sub_project.py b/sub_project/models/sub_project.py
index 81a8e68..6ba3efe 100755
--- a/sub_project/models/sub_project.py
+++ b/sub_project/models/sub_project.py
@@ -12,22 +12,21 @@ class SubProject(models.Model):
 
     @api.onchange('parent_project', 'sub_project')
     def onchange_parent_project_sub_project(self):
-        user_list = []
         if self.parent_project.sub_project:
-            user_list = self.parent_project.sub_project.ids
-            user_list.append(self._origin.id)
-            self.parent_project.sub_project = user_list
+            if self.parent_project:
+                user_list = self.parent_project.sub_project.ids
+                user_list.append(self._origin.id)
+                self.parent_project.sub_project = user_list
+            else:
+                self.parent_project.sub_project = self.ids
         if self.sub_project:
             for rec in self.sub_project:
-                #print('AAAAAAAAAAA', rec, rec._origin.id)
                 sub_project = self.env['project.project'].search([('id', '=', rec._origin.id)], limit=1)
-                #print('BBBBBBBBBBB', sub_project, self._origin.id)
                 sub_project.write({'parent_project': self._origin.id})
 
 
 
 
-
 class InheritProjectTask(models.Model):
     _inherit = 'project.task'