Borders and Shading

I go to Format>Borders and Shading>Shading tab> then down
to patterns. I then browse to my image that I want. Set
the vertical and hotizantal position. Set repeat as "no-
repeat". Then I have tried both scroll and fixed for
attachment.
Click ok
Start typing in the box. Text in the box is over the
image. The box expands past picture, so does the text.
My problem is I do not see a difference when I tried the
scroll or the fixed in the attachment box. They both seem
to view the same on my web page even in preview.

Am I missing something here?

Thank you!
Tammie