Simple ntuple problems

Hi, Im working on a fairly simple program, though obviously I am stumped. IIn the following program I've used the syntax I saw in similar (working) program. What I am trying to do is read ininformation stored in an array of objects and use that info to build an ntuple. I then want to simply draw the ntuple in a histogram. Im getting an sigmentation error on the line
lpntuple->Draw( bla ) ;

Thanks, Andy

By the way, I`m having trouble cutting and pasting code from Emacs into this field – if someone can tell me how to do that I would be grateful. As a result of my inability to do this, my code is attached.
latticedisplay.h (1.4 KB)

When closing the file, the ntuple lpntuple is automatically deleted.
Your pointer becomes invalid.
-do not close teh file
-or read the ntuple header from the newly connected file

Rene Brun