xlibs-dev problem

["Scott J. Vaverchak" <suadeo@home.com>]

Ok this is what happened:

I ran "gcc     Concept1.c      -I. -I/usr/include/GL/glut.h
-L/usr/local/lib -lglut -lGL -lGLU -lm -lX11 -lXext -lXmu -libXi
-o Concept1"

And got this for an error:

/usr/bin/ld: cannot find -lX11
collect2: ld returned 1 exit status
make: *** [Concept1] Error 1

So I did apt-get install xlibs-dev. Soon after 
I tried the gcc string again. Same error code.
Does anyone know howto fix this? 

Thank you,

Scott J. Vaverchak