Dumb question on Extents

[Grzegorz Myrda]

> I'm having problems getting my first map to come up.  So far all I'm
> getting is a blank page, which raises the following questions.  (Please
> excuse me, but I have no GIS training).

MapExtent is in units features are stored in shapefile (you can 
check it with ArcExplorer, different units are only for scalebar 
computations). But the most likely reason of getting blank page is 
that there is no access to shapefile (bad filename, path or 
something). Mapserver doesn't generate errors in such a cases, 
but pass to next layer.  If none of layers are accessible then there 
is a blank page. 

Grzegorz