Error installing zaptel on fc6

Hello i am trying to install zaptel on fedora core 6 getting this error
[root@localhost zaptel-1.4.11]# make
make[1]: Entering directory /usr/src/zaptel-1.4.11/menuselect' make[2]: Entering directory/usr/src/zaptel-1.4.11/menuselect’
gcc -g -c -D_GNU_SOURCE -Wall -c -o menuselect.o menuselect.c
gcc -g -c -D_GNU_SOURCE -Wall -c -o strcompat.o strcompat.c
gcc -g -c -D_GNU_SOURCE -Wall -c -o menuselect_curses.o menuselect_curses.c
make[3]: Entering directory /usr/src/zaptel-1.4.11/menuselect/mxml' if test -f config.status; then \ ./config.status --recheck; \ ./config.status; \ else \ ./configure; \ fi checking for gcc... gcc checking for C compiler default output file name... a.out checking whether the C compiler works... yes checking whether we are cross compiling... no checking for suffix of executables... checking for suffix of object files... o checking whether we are using the GNU C compiler... yes checking whether gcc accepts -g... yes checking for gcc option to accept ANSI C... none needed checking for g++... g++ checking whether we are using the GNU C++ compiler... yes checking whether g++ accepts -g... yes checking for a BSD-compatible install... /usr/bin/install -c checking for ranlib... ranlib checking for ar... /usr/bin/ar checking for cp... /bin/cp checking for ln... /bin/ln checking for mkdir... /bin/mkdir checking for nroff... /usr/bin/nroff checking for rm... /bin/rm checking for strdup... yes checking for vsnprintf... yes configure: creating ./config.status config.status: creating Makefile config.status: creating mxml.list config.status: creating mxml.pc config.status: creating config.h touch config.h gcc -O -Wall -O -Wall -O -Wall -O -Wall -O -Wall -O -Wall -c mxml-attr.c gcc -O -Wall -O -Wall -O -Wall -O -Wall -O -Wall -O -Wall -c mxml-entity.c gcc -O -Wall -O -Wall -O -Wall -O -Wall -O -Wall -O -Wall -c mxml-file.c gcc -O -Wall -O -Wall -O -Wall -O -Wall -O -Wall -O -Wall -c mxml-index.c gcc -O -Wall -O -Wall -O -Wall -O -Wall -O -Wall -O -Wall -c mxml-node.c gcc -O -Wall -O -Wall -O -Wall -O -Wall -O -Wall -O -Wall -c mxml-search.c gcc -O -Wall -O -Wall -O -Wall -O -Wall -O -Wall -O -Wall -c mxml-set.c gcc -O -Wall -O -Wall -O -Wall -O -Wall -O -Wall -O -Wall -c mxml-private.c gcc -O -Wall -O -Wall -O -Wall -O -Wall -O -Wall -O -Wall -c mxml-string.c /bin/rm -f libmxml.a /usr/bin/ar crvs libmxml.a mxml-attr.o mxml-entity.o mxml-file.o mxml-index.o mxml-node.o mxml-search.o mxml-set.o mxml-private.o mxml-string.o a - mxml-attr.o a - mxml-entity.o a - mxml-file.o a - mxml-index.o a - mxml-node.o a - mxml-search.o a - mxml-set.o a - mxml-private.o a - mxml-string.o ranlib libmxml.a make[3]: Leaving directory/usr/src/zaptel-1.4.11/menuselect/mxml’
gcc -o menuselect menuselect.o strcompat.o menuselect_curses.o mxml/libmxml.a mxml/libmxml.a -lncurses
make[2]: Leaving directory /usr/src/zaptel-1.4.11/menuselect' make[1]: Leaving directory/usr/src/zaptel-1.4.11/menuselect’
make[1]: Entering directory /usr/src/zaptel-1.4.11' echo "You do not appear to have the sources for the 2.6.18-1.2798.fc6 kernel installed." You do not appear to have the sources for the 2.6.18-1.2798.fc6 kernel installed. exit 1 make[1]: *** [modules] Error 1 make[1]: Leaving directory/usr/src/zaptel-1.4.11’
make: *** [all] Error 2

Please help

Look at the error that it gives you echo "You do not appear to have the sources for the 2.6.18-1.2798.fc6 kernel installed."
You do not appear to have the sources for the 2.6.18-1.2798.fc6 kernel installed.

You need to install the kernel sources/header. Run yum list kern* and post it here.