Skitter jQuery Slideshow - needs to set time interval

I found this awesome jQuery slideshow called Skitter. it's amazing! so I implemented it in my last project. You can change the time interval between two images. I have searched this every time on my website and in javascript files. on jquery.skitter.js page below shows the lines

interval: 2500,
interval_in_elements: 300, // Animation interval for hover elements hideTools interval_out_elements: 500, // Interval elements for hideTools animation

I changed those, but those lines, but no effect.

my code

<script>
$(document).ready(function() {

var options = {};

if (document.location.search) {
    var array = document.location.search.split('=');
    var param = array[0].replace('?', '');
    var value = array[1];

    if (param == 'animation') {
        options.animation = value;
    }
    else if (param == 'type_navigation') {
        if (value == 'dots_preview') {
            $('.border_box').css({'marginBottom': '40px'});
            options['dots'] = true;
            options['preview'] = true;
        }
        else {
            options[value] = true;
            if (value == 'dots') $('.border_box').css({'marginBottom': '40px'});
        }
    }
}
$('.box_skitter_large').skitter({interval: 3000});
$('.box_skitter_large').skitter(options);

// Highlight
$('pre.code').highlight({source:1, zebra:1, indent:'space', list:'ol'});

});
</script>   
< div class="box_skitter box_skitter_large">

    <ul>        
    <?php 
    $galClass           =   "cube,cubeRandom,block,cubeStop,cubeHide,cubeSize,horizontal,showBars,showBarsRandom,tube,fade,fadeFour,paralell,paralell,blind,blind,blindHeight,directionTop,directionBottom,directionRight,directionLeft,cubeStopRandom,cubeSpread";
    $galClassArray      =   array_filter(explode(',',$galClass));

    foreach($getall_img as $all_image)  
    {
        if($all_image!='')
        {
            shuffle($galClassArray);
    ?>
            <li>
                <a href='<?php echo $all_image["img_link"];?>' target="_blank">
                    <img src="<?php echo $upload_path.$all_image["img_name"];?>" class="<?php echo $galClassArray[1];?>" width="950" height="320" />
                </a>
            <?php /*<div class="label_text"><p><?php echo $all_image["img_title"];?></p></div>*/?>
           </li>    

    <?php 
        } 
    }
    ?> 
    </ul>
</div>