mkifs - what am i doing wrong ?

I’m trying to create an image file using mkifs. Thought i’d start with the
example in the help file as follows :-
[virtual=x86,bios] .bootstrap = {
startup-bios
PATH=/proc/boot procnto
}

[+script] .script = {
devc-con -n9 &
reopen /dev/con1
[+session] esh
}
libc.so.1
[data=copy]
devc-con
esh
[type=link] /usr/lib/ldqnx.so.1=/proc/boot/libc.so.1


however when I type mkifs simple.bld simple.ifs i get an error which is
invalid file name specification. Can any one help ??