Snaps? Constraints?

[hereagain]

I am going crazy trying to figure out how the coordinate system in max works. Im trying to draw a spline to use as a loft path for a curb, but everytime i try to align it along the same plane as the top of the slab the building sits on, I end up with vertices all over in 3D space. I've tried 2D, 2.5D and 3D snaps. Does anyone know of a coherent tutorial or explanation on how these work? I have just about every 3D Max book there is, and all of their explanations are lacking, to say the least. Thanks for the help.

[ipxstudios]

try the vertex snap and follow the curbside - then use the sweep modifier instead of lofting.

[Ricardo Eloy]

2D: only recognizes points in 2 dimensions (i.e., when Z=0)

3D: recognizes any point, anywhere. When creating an object with this one on, the object will be created at the same Z point of the object you're snapping to

2.5D: a blend between the two above. Recognizes points anywhere in the Z space, but objects will be created at that point's projection on the ground plane (Z=0).