In AutoCAD 2006,

According to Help, Extrude can "create solids by extruding selected objects. You can extrude closed objects such as polylines, polygons, rectangles, circles, ellipses, closed splines, donuts, and regions."

However, no matter what, I can't get it to work on a rectangle.  Or even a closed polyline.  I've tried converting the object to a region, but Extrude always reports "A 3D solid must be selected.  No solids detected."

So how can I convert such a 2D object to a 3D solid?

Thanks in Advance,
Roger

Thanks, how do I do that?

But first, I solved my own problem.  I found that if I use the Extrude from the Draw/Solids menu, it accepts the rectangle.  So I can accomplish my task, but don't understand why one works, but the other does not.

When I try to use Extrude from the tool bar on my workspace, it reports "No solids..."  When I use the command line or the Draw/Solids menu, it accepts the rectangle or polyline.

I looked for Pickfirst in Help, but all I found was info that it was saved in the Registry--no instructions on how to access it.  Do I have to use regedit and actually edit the Windows Registry?  That seems rather awkward.

Thanks,
Roger