Xlib: extension "GLX" missing on display ":2.0".

Hello,
I am a beginner in CUDA C programming.
I have compiled 'julia_gpu.cu successfully. But now I cannot run binary ‘julia_gpu’ due to this error:

user@computer:~/CUDA/CUDA/chapter04$ nvcc -lglut -o julia_gpu julia_gpu.cu
user@computer:~/CUDA/CUDA/chapter04$ ./julia_gpu Xlib: extension “GLX” missing on display “:2.0”.
freeglut OpenGL GLX extension not supported by display ‘:2.0’

I am using Ubuntu 10.04 LTS, CPU XEON Nehalem X5550
2x Nvidia Tesla C1060
and VGA compatible controller Matrox Graphics.

Please help me.

Bekdaulet