You are reloading several different versions of jquery causing conflicts.
Remove the lines at the bottom:
<script src="slideshow/js/jquery-1.8.2.min.js"></script>
<script src="slideshow/js/revolver.min.js"></script>
<script src="slideshow/js/slideshow.js"></script>
<script src="brand-slider/js/jquery-1.8.2.min.js"></script>
<script src="brand-slider/js/revolver.min.js"></script>
<script src="brand-slider/js/slideshow.js">
Remove both references to: /jquery-1.8.2.min.js
and probably only keep one or the other copies of the other two because I'm guessing they are repetitive as well.