how to compile a kernel module?

[watermelon]

When I try to install a module by using "insmod XXX.o", the system tells me that "couldn't find the kernel version the module was compiled for". The command I use to compile a module is:
"gcc -c -Wall -D__KERNEL__-DMODULE XXX.c"

Could anybody tell me what's wrong? Thanks a million!!!

[Strike]

try tacking on a -DMODVERSIONS to your command line stuff