Source code for sendsms

Dear Everybody,

I downloaded the kannel 1.2.0 package from:

http://www.kannel.3glab.org/download.shtml

unzipped and untarred it and was finding a
way to send a ringtone to my mobile phone. I came
across the sendsms program which I believe can
send a normal SMS or a picture message (ringtone/operator logo).

However I need to customize this application. For this
I have to make changes in the source code of sendsms, which
I could not find in the source tarball: gateway-1.2.0.tar.gz

Where can I find the source code for the sendsms program? If
sendsms is a third-party contribution to the development of the
Kannel package then can the contributor come forward and
provide his mail id?

Eagerly awaiting a positive response.

SNODX

Please Note: I got irrelevant results while searching for
             the link to the source code of sendsms in
             the devel and users list at kannel.3glab.org
             and also while searching Google. I am continuing
             the search effort however.