DAHDI 2.6.1 does not build in Linux kernel 3.8.0-29-generic


I downloaded source codes of DAHDI 2.6.1 and Linux Kernel 3.8.0-29-generic.

When I typed sudo apt-get install linux-headers-$(uname -r) to install linux kernel header I got the message as shown below:

I am facing problem when I try to compile and install DAHDI on my UBUNTU Server. It displays me the messages displayed below:

I am a newbie in this regard. Kindly help me figuring the problem out, and also guide me to the solution of the problem. It’s a bit urgent!

Nazish Kanwal