Loading screen?

So I made a portal box On a door that when you walk through it, you get teleported to whats on the other side, which is what I want it too do, But I want a loading screen in between teleporting from one side of the door to the other, could it be possible to make another level that’s the loading screen and just make it stay for a few seconds and then put you in the new level on the other side of the door. I don’t know if that’s confusing but it might be. There is a screenshot of how I have the portal set up, thanks to anyone who responds.

This link is a good tutorial on how to do so… It shows how to make portals and then add a loading screen. link text