Dynamic image scroller

Hi guys,

Its been a while since I was here…

I have been trying to figure out how to create this movieclip
I have a bunch of images which is laid out horizontally (x axis).
The functionality is very simple, when I click on the movieclip it will allow me to drag it from right to left and vice versa. This part is simple enough. I face a problem when it comes to the end and the beginning of the movieclip. How do I make it undraggable when it reaches the end of the movie clip and vice versa when I drag it back to the beginning.

An example of what im looking to do is http://graphictherapy.com/index2.html
This is pretty much the same effect that I want to use.

Thanks,
vazash