Multiple teleporting universes?

So in my game it involves teleporting from 1 place to another a lot. Heres like an example server 1 = looby(starting spot, teleports you to server 2) server2= game(can go to server 3 or 4) server3(gos to server 3) server 4 (goes to server 2)

How do I make this work? Because server 1 can teleport to server 2 but the others crash when I try to teleport them

Here is a useful guide to Universes in Roblox, and Teleporting between places: http://wiki.roblox.com/index.php?title=Game