I'm writing an app that I may want to insert into a bigger project later as a separate dialog. I'm curious if the IDs for things in the resource have to be completely unique to the project, or only to the specific resource/dialog? Like can a control in 1 dialog have the same ID number as a control in another dialog? The reason I'm questioning this at all is that all the functions like GetDlgItem() require a handle to the specific dialog which contains the control. That leads me to believe I can order my controls anyway I please so long as they're in a separate dialog.