how can add a new video to an excited project

[Morteza-R]

when we produce a DVD project .how can add a new video without lost the project files.
IN ADDING A NEW VIDEO the previous project will be lost and converting will be begin and lost produced files
how can add only new one to this DVD

[JJ]

Are trying to add to already converted dvd files?
You can't.

You need to open project and add video to that project before converting anything on that project.