Wanted: Help centering Text

I'm having trouble centering text. Given a coordinate, I want the option of 
centering text vertically, horizontally, both vertically and horizontally.

I've been experiment with text-align and text-anchor and I read the 
documentation at the wc3 site.

What I am doing seems to have no affect. I cannot determine if I am stupid 
or Mozilla is broken.It seems to me that adding text-anchor="end" or 
text-align="middle" should have some affect but it does not.

Perhaps someone could provide me with a working example?

Thanks!
Siegfried