You can do it that way also. Depends on the way you do your business logic. :) This posting is provided "AS IS" with no warranties, and confers no rights. Alex Korchemniy

Thanks for the answer sreejith ss nair. I also found good info at MSDN about Validating. http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfsystemwindowsformscontrolclassvalidatedtopic.asp[^]

Thanks a lot, it works but SelectedNode doesn´t work with right click so I use: private bool IsSubNode() { TreeNode selected =treeview.GetNodeAt(this.treeview.PointToClient(Cursor.Position)); if (selected != null) { if (selected.Parent != null) return true; } return false; } GetNoteAt with Current Mouse Position works with right click, now subnode works, and I can follow with my little app, thank you :)