What is the change user command?

What is the command for changing user without logging off? I can't find it in the close command ...

It's currently not supported unfortunately, but it's an easy addition - I'll see if we can get this into the next release.

True...I know that most people don't use it. But sometimes it's usefull when my brother wants to use the pc and I have some things running...Can't it be done with a link to a .vbs script?