help installing glhack
 

im sure this is pretty easy but i dont really know what to do

im installing glhack (nethack's 2d graphic version) and when i write 'make', i get this output:

[root@localhost glhack-1.1]# make
( cd src ; make )
make[1]: Entering directory `/home/nef/downloads/software/glhack/glhack-1.1/src'
touch ../src/config.h-t
make[1]: sdl-config: Command not found
cc -O -Wall -I../include -c monst.c
make[1]: sdl-config: Command not found
cc -O -Wall -I../include -c objects.c
make[2]: Entering directory `/home/nef/downloads/software/glhack/glhack-1.1/util'
cc -O -Wall -I../include -c -o makedefs.o makedefs.c
cc -o makedefs makedefs.o ../src/monst.o ../src/objects.o
make[2]: Leaving directory `/home/nef/downloads/software/glhack/glhack-1.1/util'
make[2]: Entering directory `/home/nef/downloads/software/glhack/glhack-1.1/util'
./makedefs -p
make[2]: Leaving directory `/home/nef/downloads/software/glhack/glhack-1.1/util'
make[2]: Entering directory `/home/nef/downloads/software/glhack/glhack-1.1/util'
./makedefs -o
make[2]: Leaving directory `/home/nef/downloads/software/glhack/glhack-1.1/util'
touch ../src/hack.h-t
make[1]: sdl-config: Command not found
cc -O -Wall -I../include -c -o allmain.o allmain.c
make[1]: sdl-config: Command not found
cc -O -Wall -I../include -c -o alloc.o alloc.c
make[1]: sdl-config: Command not found
cc -O -Wall -I../include -c -o apply.o apply.c
make[1]: sdl-config: Command not found
cc -O -Wall -I../include -c -o artifact.o artifact.c
make[1]: sdl-config: Command not found
cc -O -Wall -I../include -c -o attrib.o attrib.c
make[1]: sdl-config: Command not found
cc -O -Wall -I../include -c -o ball.o ball.c
make[1]: sdl-config: Command not found
cc -O -Wall -I../include -c -o bones.o bones.c
make[1]: sdl-config: Command not found
cc -O -Wall -I../include -c -o botl.o botl.c
make[1]: sdl-config: Command not found
cc -O -Wall -I../include -c -o cmd.o cmd.c
(it continues like that a long way)

do you have any idea why this is happening???