A lot of errors compiling app_conference

i’m trying to compile app_conference for Asterisk v.1.4.12 and i get these errors:

I modified the following Makefile as shown:

Please may someone help me?
Thankyou very much.

Those are compiler errors which m
ake me think you have not included some things in your Linux install.

Make sure you read the Make messages and see what could be missing you need to install.