[SR-Users] problem in MAKE command during installation Sip Express Router

[city spider]

hello
i want to install Sip Express Router on CENT OS 5.5.
the problem is that after untar the ser-0.9.6.src.tar.gz package my
system doesn't operate MAKE command ,and returns 127 errors containing
message "the system doesn't find the folder...."

is there any solution for this problem...
waiting for your response.