jQuery SimplyScroll - moveBack function question

Question

I am working on a project that uses SimplyScroll to scroll the images auto scroll infinitely. Like this example (http://www.logicbox.net/jquery/simplyscroll/horizontal.html). At the same time, I want to add buttons on each side allow the user to scroll and forth by the direction of they are clicking.

So, I have hover event to pause the scroll, apply the "moveForward" & "moveBack" functions to each of the button, I couldn't seem to get the button and use the built in "moveForward()" & "moveBack()" work. The moveFoward() "kind" of worked, but not moveBack. I know I need to do some modification to the moveBack function, but my jQuery skill isn't that l33t to get it working.

Any help will be greatly appreciated.

Thanks in advance