尾波滑块偏移

Question

我希望我的图像居中 有人知道如何在尾声滑块中设置动态偏移？ div类面板只是图像的宽度，因此图像之间只有9px

var scrollOptions = {
    target: $scroll, // the element that has the overflow
    items: $panels,
    navigation: '.navigation a',
    prev: 'img.left', 
    next: 'img.right',
    axis: 'xy',
    onAfter: trigger,

    // do i need a dynamic offset to center my images?
    // each image has different width
    // and the div class panel is only width of the image
    offset: offset,

    duration: 500,
    easing: 'swing'
};



<div id="slider">    
    <div class="scroll">
        <div class="scrollContainer">
                <div class="panel" id="image1"><img src="data/8f8bc5cb2fdac666c9534f7c4b78c010.jpg" alt="" /></div>
                <div class="panel" id="image2"><img src="data/31f3ae0aac735d2b9432e88108e75b86.jpg" alt="" /></div>
                <div class="panel" id="image3"><img src="data/42a4c582d65e46dda4ddcde70a5b2afc.jpg" alt="" /></div>
                <div class="panel" id="image4"><img src="data/30c32091eb1121f630c48016b04a6f04.jpg" alt="" /></div>

        </div>
    </div>

    <div class="scroll-bar"></div>

    <div class="photo-thumb-block">
        <div class="photo-thumb"><a href="#image1"><img src="small/8f8bc5cb2fdac666c9534f7c4b78c010.jpg" style="width:159px;height:119px;" alt="" /></a></div>
        <div class="photo-thumb"><a href="#image2"><img src="small/31f3ae0aac735d2b9432e88108e75b86.jpg" style="width:159px;height:119px;" alt="" /></a></div>
        <div class="photo-thumb"><a href="#image3"><img src="small/42a4c582d65e46dda4ddcde70a5b2afc.jpg" style="width:159px;height:119px;" alt="" /></a></div>
        <div class="photo-thumb last"><a href="#image4"><img src="small/30c32091eb1121f630c48016b04a6f04.jpg" style="width:159px;height:119px;" alt="" /></a></div>
    </div>
</div>

请看这里 http://tradinx.com/codatest/

thanx求助