Thank you Hans. The picture/example speaks a thousand words. Excellent...the sloping wall example works well and is how I intend to use it.

I am trying to intall Sketchup under windows vista. Tried several more times but still same problem. I take it it is a program and has an icon etc? I have now posted problem to Google SU forum as I cannot find other examples of this problem. I do not get any error messages as others do when install fails.