Need a little help with this JS script

[Site Owner]

I have this script that shows a picture slide show from a database...
<script language="javascript">
var imgArray=new Array({$num_pictures});
var switchImage={$set_slideShow_sec};
var switchImageCountFrom={$set_slideShow_count_from};
{foreach item=image from=$image_list}
imgArray[{$image.nr}]="{$image.file}";
{/foreach}
</script>
However it lacks controllers...you know "<< prev | next >>".

And I have no idea as I'm a noob to JS...

Hmm...This thing uses Smarty Engine so I don't know what the variables are set to...I can look if it's needed.