app_conference install

i try to install app_conference on asterisk version 1.2. but failed .
it said like the following :
/usr/include/asterisk/file.h :56:error:syntax error before ‘’ token
/usr/include/asterisk/file.h :57:error:syntax error before '
’ token

but the same file can install on asterisk version 1.0.9 .i check the gcc
the forer is :3.4.3
the later is :3.2.4

how to do? thanks in advance .
btw : app_conference and meetme which is more better? app_conference allow only one speaker at one time?

i have got it .just do like it hints,add '#include <stdio.h> ’ in file.h.
but there is another strange thing. when i finished the install and run
asterisk ,meetme application disappear. meetme and conference can not coexist? any reply will be appreciated! :smile: .