OpenGL Hello World Example

[Rohit]

Hi, 
This is something that has troubled me quite a bit. I followed the hello world 
tutorial for opengl found here. 

http://www.eecs.tulane.edu/www/Terry/OpenGL/Simple_Example.html#A%20Simple%20Example

This is the command I'm using to compile it (as suggested at the website)

gcc -o Hello_World Hello_World.c -lX11 -lMesaGL -lMesaGLU -lMesatk -lm 

However it says gltk.h not found when I have gltk.h in 
/usr/X11R6/include/GL/gltk.h

This is the same type of scenario I ran into when I tried compiling qt 
examples. I have tried appending  I/usr/X11R6/include/GL/gltk.h to the above 
gcc command.


Any advice will be greatly appreciated. 

Thanks
Rohit