Send a message to facebook user

Hi webmasters, I have sms notifications on my account and want to let visitors send messages to my facebook via web from X websites without them being logged or needing to create a facebook account.

I’m researching on how to do this but I’m confused. I know I have to create a facebook app to connect with my server script. Anyone have done this before?.

I already found info to creat an app and make X script post info on my wall but the wall is public, I want it to send messages. This way I could set the script to send messages from a main account to a salesman account and thus, to their cell phone via sms.

I’m skilled at Perl but I find all of these more suitable for PHP, there is no problem on that, just the documentation.

Any help will be appreciated.