Help with starting the debugger

[pat]

Has anyone gotten the debugger to work? Please yes, please help.

On my Windows XP computer, when I typed im() after compiling my test
module with the debug_info option, the shell crashes with the message:
"werl.exe has encountered a problem and needs to close." When I do
this on my Ubantu Server installation, I get the following:

Application initialization failed: no display name and no $DISPLAY
environment variable
Error in startup script: no display name and no $DISPLAY environment
variable
"load /usr/lib/libtk8.4.so.0 Tk"
("Package ifneeded" script)
invoked from within
"package require Tk8.3"
(file "/usr/lib/erlang/lib/gs 1.5.10/priv/gstk.tcl"

Thanks,
Pat