i have fedora red hat 9 2.4.22-1,2115.nptl

i saw an exampes that have the line

#include <asm/uaccess.h>

but in the directory usr/include/asm

i dont have the file uaccess.h

so i can not run the example

is anyone know the solution?
why i dont have there the file uaccess.h?

It may depends on a distro. In my MDK 9.1 it's in glibc-devel package.

It's actually part of the kernel. If you have the sources (I'll gather MDK doesn't give them to you by default, it's why you get them in the devel packages) you'll find them under include/asm/. That's if you've configured the kernel, (asm is a symmlink to your architecture), otherwise you're most likely interested in include/asm-i386.
The kernel sources if you have them will be found in /usr/src/linux (linux again being a symmlink to your current (usually unless something went wrong somewhere along the way) kernel). Just ls /usr/src and pick out your kernel if it's different (you should probably link it to /usr/src/linux though, because otherwise kernel-dependant things you build will be compiled against the wrong headers, this may or may not break things).