Delay without viz.waittime?

[Johannes]

Hi,
how do I put a delay inside my skript?
without viz.waittime which stalls the whole scene.

I want a projector screen to move down bevor graphs get put on it.

If I do:

screenWall.goto(0,-2.2,0, .8)
putGraphOnScreenWall()

the graphs are on the ScreenWall before it is down...

Thank you,
Johannes