Question: I don't want to share my PAGE, but I want to share a message with a short URL link to something.

Answer: 
I think you are looking for the Facebook API stream.publish function:

<http://wiki.developers.facebook.com/index.php/Stream.publish>

or FB.Connect.streamPublish:

<http://developers.facebook.com/docs/?u=facebook.jslib.FB.Connect.streamPublish>
Here's a very easy way to do it: <http://www.facebook.com/facebook-widgets/share.php>