加载中进行等待图像的技术

<div class="rg-image-wrapper">        
   <div class="rg-image-nav">   
    <a style="display: block; width: 50%; cursor: url('/templets/default/images/move-prev-next/bg11.cur'), auto; height: 100%; outline: medium none;" class="rg-image-nav-prev" href="#">Previous Image</a>    
   <a style="display: block; width: 50%; cursor: url('/templets/default/images/move-prev-next/bg12.cur'), auto; height: 100%; outline: medium none; " class="rg-image-nav-next" href="#">Next Image</a>         
     </div>
     <div class="rg-image"><img src="/uploads/121101/1-1211010U6009C-widthMax-540-auto.jpg">
     </div>     
     <div class="rg-loading" style="display: none;"></div>    
</div>

class="rg-loading" 的图像是 正常情况下是隐藏,在加载的过程中就显示, (它当然是绝对定位,显示在上面)加载完毕就隐藏